# UVa 438 – The Circumference of the Circle

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

double dist(double x1, double y1, double x2, double y2)
{
return sqrt(sqr(x1-x2)+sqr(y1-y2));
}

int main()
{

///freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

double x1,y1,x2,y2,x3,y3;
while(cin>>x1>>y1>>x2>>y2>>x3>>y3)
{
double a,b,c;

//calculating the three side of the triangle

a=dist(x1,y1,x2,y2);
b=dist(x2,y2,x3,y3);
c=dist(x1,y1,x3,y3);

// calculating the sub perimeter

double s=(a+b+c)/2.0;

// calculating the area of the triangle.

double area=sqrt(s*(s-a)*(s-b)*(s-c));

// calculating radius using formula area= (a*b*c)/(2*R) ; here R = diameter

double r=(a*b*c)/(4.0*area);

cout<<setprecision(2)<<fixed<<Pi*2.0*r<<endl;

}

return 0;
}

```

# Light OJ: 1348 – Aladdin and the Return Journey

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

inline void inp( int &n )
{
n=0;
int ch=getchar_unlocked();
int sign=1;
while( ch < '0' || ch > '9' )
{
if(ch=='-')sign=-1;
ch=getchar_unlocked();
}
while(  ch >= '0' && ch <= '9' )
n = (n<<3)+(n<<1) + ch-'0', ch=getchar_unlocked();
n=n*sign;
}

#define mx 30005

vector<int>g[mx];
int gini[mx];
int n;

int par[mx],level[mx], max_subtree[mx];
int sparse_par[mx][17];

int node_serial[mx],serial_node[mx];
int chain_no,indx;

ll tree[mx];

int dfs(int u, int from, int cnt)
{
sparse_par[u][0]=from;
level[u]=cnt;
int node=-1, maxi=0, total=1;
for(int i=0; i<SZ(g[u]); i++)
{
int v=g[u][i];
if(v!=from)
{
int temp=dfs(v,u,cnt+1);
total+=temp;
if(temp>maxi)
{
maxi=temp;
node=v;
}
}
}

max_subtree[u]=node;
}

void build_table(int n)
{
for(int j=1; 1<<j<=n; j++)
{
for(int i=0; i<n; i++)
{
sparse_par[i][j]=sparse_par[sparse_par[i][j-1]][j-1];
}
}
}

int LCA_query(int p, int q)
{
if(level[p]<=level[q]) swap(p,q);
int log=log2(level[p]);

for(int i=log; i>=0; i--)
{
if(level[p]-(1<<i)>=level[q])
p=sparse_par[p][i];
}
if(p==q) return p;

for(int i=log; i>=0; i--)
{
if(sparse_par[p][i]!=sparse_par[q][i])
{
p=sparse_par[p][i];
q=sparse_par[q][i];
}
}

return sparse_par[p][0];
}

void HLD(int u, int sz)
{
chain_indx[u]=chain_no;
chain_size[chain_no]=sz;

node_serial[u]=indx;
serial_node[indx]=u;
indx++;
if(max_subtree[u]==-1) return ;

HLD(max_subtree[u],sz+1);

for(int i=0; i<SZ(g[u]); i++)
{
int v=g[u][i];
if(v!=sparse_par[u][0] && v!=max_subtree[u])
{
chain_no++;
HLD(v,1);
}
}
}

void update(int idx, int val)
{
while(idx<=indx)
{
tree[idx]+=val;
idx+=(idx&-idx);
}
}

ll query(int a, int b)
{
ll ret=0;
ll ret2=0;
while(b)
{
ret+=tree[b];
b-=(b & -b);
}
a--;
while(a)
{
ret2+=tree[a];
a-=(a&-a);
}
return ret-ret2;
}

ll query_tree(int a, int b)
{
ll ret=0;
while(chain_indx[a]!=chain_indx[b])
{
}
ret+=query(node_serial[b],node_serial[a]);
return ret;
}

void update_tree(int a, int val)
{
update(node_serial[a],gini[a]*-1);
update(node_serial[a],val);
gini[a]=val;
}

inline void allclear(int n)
{
chain_no=1;
indx=1;
for(int i=0; i<=n; i++)
{
g[i].clear();
}

ms(tree,0);
}

int main()
{

//    freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

int t;
scanf("%d",&t);
TEST_CASE(t)
{
scanf("%d",&n);
for(int i=0; i<n; i++) scanf("%d",&gini[i]);
allclear(n+2);
for(int i=1; i<n; i++)
{
int a,b;
scanf("%d %d",&a,&b);
g[a].pb(b);
g[b].pb(a);
}

dfs(0,0,1);
build_table(n);
HLD(0,1);

for(int i=1; i<indx; i++)
{
update(i,gini[serial_node[i]]);
}

int m;
scanf("%d",&m);
LINE_PRINT_CASE;
while(m--)
{
int a,b;
scanf("%d",&a);
if(a==0)
{
scanf("%d %d",&a,&b);
int lca=LCA_query(a,b);
ll ans=query_tree(a,lca);
ans+=query_tree(b,lca);
ans-=gini[lca];
printf("%lld\n",ans);
}
else
{
scanf("%d %d",&a,&b);
update_tree(a,b);
}
}
}

return 0;
}

```

# Light OJ: 1315 – Game of Hyper Knights

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

int fx[]= {-2,-3,-2,-1,-1,+1};
int fy[]= {+1,-1,-1,-2,-3,-2};

int dp[2003][2003];

inline bool valid(int x,int y)
{
if(x<0 || y<0) return 0;
return 1;
}

int func(int x, int y)
{
int &ret=dp[x][y];
if(ret!=-1) return ret;

int cnt=0;
for(int i=0; i<6; i++)
cnt+=valid(x+fx[i],y+fy[i]);
if(cnt==0) return ret=0;

set<int>st;

for(int i=0; i<6; i++)
{
if(valid(x+fx[i],y+fy[i]))
st.insert(func(x+fx[i],y+fy[i]));
}

int p=0;

while(st.find(p)!=st.end()) p++;
return ret=p;
}

int main()
{

//    freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

int t;
sf(t);

ms(dp,-1);

TEST_CASE(t)
{
int n;
sf(n);

int ans=0;

for(int i=0; i<n; i++)
{
int a,b;
sff(a,b);
ans^=func(a,b);
}

PRINT_CASE;
if(ans)
{
pf("Alice\n");
}
else
pf("Bob\n");

}

return 0;
}

```

# Light OJ : 1296 – Again Stone Game

0

Solution Idea: Just Find the pattern for smaller input and get AC ðŸ˜›

```

#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

int main()
{

///freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

int t;
sf(t);
TEST_CASE(t)
{
int n;
sf(n);

int ans=0;

for(int i=0;i<n;i++)
{
int a;
sf(a);
while(a%2)
{
a/=2;
}
ans^=a/2;
}

PRINT_CASE;
if(ans)
pf("Alice\n");
else
pf("Bob\n");

}

return 0;
}

```

# Light OJ: 1199 – Partitioning Game

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

int dp[10005];

int func(int n)
{
if(n==1 || n==2) return 0;

if(dp[n]!=-1) return dp[n];

set<int>st;

int mid=n/2;
if(n%2==0) mid--;

for(int i=1;i<=mid;i++)
{
st.insert(func(i)^func(n-i));
}

int ret=0;
while(st.find(ret)!=st.end()) ret++;
return dp[n]=ret;
}

int main()
{

///freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

ms(dp,-1);

int t;
sf(t);
TEST_CASE(t)
{
int n;
sf(n);

int ans=0;

for(int i=0;i<n;i++)
{
int a;
sf(a);
ans^=func(a);
}

PRINT_CASE;

if(ans)
pf("Alice\n");
else
pf("Bob\n");

}

return 0;
}

```

# UVa : 10938 – Flea circus

0

Solution Idea: Find the LCA. Then find the middle node and middle+1 node on the path connection two nodes which are given in the query. Here I use an extra DFS to find the path on a reverse graph g2.

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

#define mx 5005
int n,q;

vector<int>g1[mx],g2[mx];

int sparse_par[mx][14],sparse_dis[mx][14];

int level[mx],par[mx];

void dfs(int u, int cnt, int from)
{
par[u]=from;
level[u]=cnt;
g2[u].pb(from);

for(int i=0;i<SZ(g1[u]);i++)
{
int v=g1[u][i];
if(v!=from)
{
dfs(v,cnt+1,u);
}
}
}

void build_talbe()
{
for(int i=1;i<=n;i++)
{
sparse_par[i][0]=par[i];
sparse_dis[i][0]=1;
}
sparse_dis[1][0]=0;

for(int j=1; 1<<j<=n;j++)
{
for(int i=1;i<=n;i++)
{
sparse_par[i][j]=sparse_par[sparse_par[i][j-1]][j-1];
sparse_dis[i][j]=sparse_dis[i][j-1]+sparse_dis[sparse_par[i][j-1]][j-1];
}
}
}

int LCA;

int query(int p, int q)
{
if(level[p]<=level[q]) swap(p,q);

int log=log2(level[p]);

int ret=0;

for(int i=log;i>=0;i--)
{
if(level[p]-(1<<i)>=level[q])
{
ret+=sparse_dis[p][i];
p=sparse_par[p][i];
}
}

if(p==q){LCA=p; return ret;}

for(int i=log;i>=0;i--)
{
if(sparse_par[p][i]!=sparse_par[q][i])
{
ret+=sparse_dis[p][i];
ret+=sparse_dis[q][i];
p=sparse_par[p][i];
q=sparse_par[q][i];
}
}
ret+=2;
LCA=par[p];
return ret;
}

vector<int>temp;

int dfs1(int u, int cnt)
{
if(u==LCA) return u;
temp.pb(u);
if(cnt==0) return u;
for(int i=0;i<SZ(g2[u]);i++)
return dfs1(g2[u][i],cnt-1);
}

int main()
{

//    freopen("in.txt","r",stdin);
//    freopen("out.txt","w",stdout);

while(sf(n) && n)
{
loop(i,n-1)
{
int a,b;
sff(a,b);
g1[a].pb(b);
g1[b].pb(a);
}

dfs(1,0,1);

build_talbe();

sf(q);

while(q--)
{
int a,b;
sff(a,b);

int dis=query(a,b)+1;

if(dis%2==0)
{
temp.clear();
dfs1(a,n);
temp.pb(LCA);
int x=SZ(temp);
dfs1(b,n);
reverse(temp.begin()+x,temp.end());
int aa=temp[(dis/2)-1];
int bb=temp[dis/2];
pf("The fleas jump forever between %d and %d.\n",min(aa,bb),max(aa,bb));

}
else
{
int p;
if(level[a]>level[b])
p=a;
else
p=b;
pf("The fleas meet at %d.\n",dfs1(p,dis/2));
}
}

for(int i=0;i<=n;i++)
{
g1[i].clear();
g2[i].clear();
}

}

return 0;
}

```

# UVa : 12238 – Ants Colony

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

#define mx 100005

int n;
int level[mx],par[mx],dis[mx];

vector<int>g[mx],cost[mx];

ll sparse_par[mx][20],sparse_sum[mx][20];

void dfs(int u, int cnt, int from)
{
par[u]=from;
level[u]=cnt;

for(int i=0;i<SZ(g[u]);i++)
{
int v=g[u][i];

if(v!=from)
{
dis[v]=cost[u][i];
dfs(v,cnt+1,u);
}

}

}

void build_table()
{
for(int i=0;i<n;i++)
{
sparse_par[i][0]=par[i];
sparse_sum[i][0]=dis[i];
}

for(int j=1;1<<j<n;j++)
{
for(int i=0;i<n;i++)
{
sparse_par[i][j]=sparse_par[sparse_par[i][j-1]][j-1];
sparse_sum[i][j]=sparse_sum[i][j-1]+sparse_sum[sparse_par[i][j-1]][j-1];
//            D(i);
//            D(j);
//            D(sparse_par[i][j]);
//            D(sparse_sum[i][j]);
}
}

}

ll query(int p, int q)
{
ll ret=0;
if(level[p]<=level[q]) swap(p,q);

int log=log2(level[p]);

for(int i=log;i>=0;i--)
{
if(level[p]-(1<<i)>=level[q])
{
ret+=sparse_sum[p][i];
p=sparse_par[p][i];
}
}

if(p==q) return ret;

for(int i=log;i>=0;i--)
{
if(sparse_par[p][i]!=sparse_par[q][i])
{
ret+=sparse_sum[p][i];
ret+=sparse_sum[q][i];
p=sparse_par[p][i];
q=sparse_par[q][i];
}
}

ret+=dis[p];
ret+=dis[q];
return ret;

}

int main()
{

//    freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

while(sf(n) && n)
{
for(int i=1;i<n;i++)
{
int a,b;
sff(a,b);
g[i].pb(a);
g[a].pb(i);
cost[a].pb(b);
cost[i].pb(b);
}

dis[0]=0;

dfs(0,0,0);

build_table();

int q;
sf(q);

bool test=1;

while(q--)
{
int a,b;
sff(a,b);

ll ans=query(a,b);

if(test)
{
printf("%lld",ans);
test=0;
}
else
{
printf(" %lld",ans);
}

}

printf("\n");

for(int i=0;i<=n;i++)
{
g[i].clear();
cost[i].clear();
}

}

return 0;
}

```

# SPOJ: LCA – Lowest Common Ancestor

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d: ",z)
#define LINE_PRINT_CASE  printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

int n,q;
int par[1005],level[1005];
vector<int>g[1005];
int sparse_par[1005][12];

void dfs(int u, int cnt, int from)
{
par[u]=from;
level[u]=cnt;

for(int i=0;i<SZ(g[u]);i++)
{
int v=g[u][i];
if(v!=from)
{
dfs(v,cnt+1,u);
}
}
}

void build_table()
{
for(int i=1;i<=n;i++)
{
sparse_par[i][0]=par[i];
}

for(int j=1;1<<j<=n;j++)
{
for(int i=1;i<=n;i++)
{
sparse_par[i][j]=sparse_par[sparse_par[i][j-1]][j-1];
//            D(i);
//            D(j);
//            D(sparse_par[i][j]);
}
}
}

int query(int p, int q)
{
if(level[p]<=level[q]) swap(p,q);
int log=log2(level[p]);

for(int i=log;i>=0;i--)
{
if(level[p]-(1<<i)>=level[q])
p=sparse_par[p][i];
}

if(p==q) return p;

for(int i=log;i>=0;i--)
{
if(sparse_par[p][i]!=sparse_par[q][i])
{
p=sparse_par[p][i];
q=sparse_par[q][i];
}
}

return par[p];

}

int main()
{

//    freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

int t;
sf(t);
TEST_CASE(t)
{
sf(n);

for(int i=1;i<=n;i++)
{
int m,a;
sf(m);
for(int j=0;j<m;j++)
{
sf(a);
g[a].pb(i);
g[i].pb(a);
}
}

dfs(1,0,1);

build_table();

sf(q);
LINE_PRINT_CASE;
while(q--)
{
int a,b;
sff(a,b);
printf("%d\n",query(a,b));
}

for(int i=0;i<=n;i++)
g[i].clear();

}

return 0;
}

```

# Light OJ: 1162 – Min Max Roads

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

#define mx 100005

int n,q;
vector<int>g[mx],cost[mx];

int par[mx], dis[mx], level[mx];

int sparse_par[mx][20],sparse_max[mx][20], sparse_min[mx][20];

void dfs(int u, int cnt, int from)
{
par[u]=from;
level[u]=cnt;

for(int i=0;i<SZ(g[u]);i++)
{
int v=g[u][i];
if(v!=from)
{
dis[v]=cost[u][i];
dfs(v,cnt+1,u);
}
}
}

void build_table()
{
ms(sparse_par,-1);

sparse_par[1][0]=par[1];
sparse_min[1][0]=INT_MAX;
sparse_max[1][0]=0;

for(int i=2;i<=n;i++)
{
sparse_par[i][0]=par[i];
sparse_min[i][0]=dis[i];
sparse_max[i][0]=dis[i];
}

for(int j=1;1<<j<n;j++)
{
for(int i=1;i<=n;i++)
{
if(sparse_par[i][j-1]!=-1)
{
//                D(i);
//                D(j);

sparse_par[i][j]=sparse_par[sparse_par[i][j-1]][j-1];
sparse_max[i][j]=max(sparse_max[i][j-1],sparse_max[sparse_par[i][j-1]][j-1]);
sparse_min[i][j]=min(sparse_min[i][j-1],sparse_min[sparse_par[i][j-1]][j-1]);
//                D(sparse_par[i][j]);
//                D(sparse_max[i][j]);
//                D(sparse_min[i][j]);
}
}
}

}

pii query(int p, int q)
{
if(level[p]<level[q]) swap(p,q);

int log=log2(level[p]);

int maxi=0,mini=INT_MAX;

for(int i=log;i>=0;i--)
{
if(level[p]-(1<<i)>=level[q])
{
maxi=max(maxi,sparse_max[p][i]);
mini=min(mini,sparse_min[p][i]);

p=sparse_par[p][i];

}
}

if(p==q)
{
return pii(mini,maxi);
}

for(int i=log;i>=0;i--)
{
if(sparse_par[p][i]!=-1 && sparse_par[p][i]!=sparse_par[q][i])
{
maxi=max(maxi,max(sparse_max[p][i],sparse_max[q][i]));
mini=min(mini,min(sparse_min[p][i],sparse_min[q][i]));
p=sparse_par[p][i];
q=sparse_par[q][i];
}
}

maxi=max(maxi,max(dis[p],dis[q]));
mini=min(mini,min(dis[p],dis[q]));

return pii(mini,maxi);

}

int main()
{

//    freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

int t;
sf(t);
TEST_CASE(t)
{
sf(n);

for(int i=1;i<n;i++)
{
int a,b,c;
sfff(a,b,c);
g[a].pb(b);
g[b].pb(a);
cost[a].pb(c);
cost[b].pb(c);
}

dis[1]=0;
dfs(1,0,1);

build_table();

sf(q);

PRINT_CASE;

while(q--)
{
int a,b;
sff(a,b);
pii ans=query(a,b);
printf("%d %d\n",ans.ff,ans.ss);

}

for(int i=0;i<=n;i++)
{
g[i].clear();
cost[i].clear();
}

}

return 0;
}

```

# Light OJ: 1128 – Greatest Parent

0

```
#include <bits/stdc++.h>

#define pii              pair <int,int>
#define pll              pair <long long,long long>
#define sc               scanf
#define pf               printf
#define Pi               2*acos(0.0)
#define ms(a,b)          memset(a, b, sizeof(a))
#define pb(a)            push_back(a)
#define MP               make_pair
#define db               double
#define ll               long long
#define EPS              10E-10
#define ff               first
#define ss               second
#define sqr(x)           (x)*(x)
#define D(x)             cout<<#x " = "<<(x)<<endl
#define VI               vector <int>
#define DBG              pf("Hi\n")
#define MOD              1000000007
#define CIN              ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define SZ(a)            (int)a.size()
#define sf(a)            scanf("%d",&a)
#define sfl(a)           scanf("%lld",&a)
#define sff(a,b)         scanf("%d %d",&a,&b)
#define sffl(a,b)        scanf("%lld %lld",&a,&b)
#define sfff(a,b,c)      scanf("%d %d %d",&a,&b,&c)
#define sfffl(a,b,c)     scanf("%lld %lld %lld",&a,&b,&c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i<n;i++)
#define loop1(i,n)       for(int i=1;i<=n;i++)
#define REP(i,a,b)       for(int i=a;i<b;i++)
#define RREP(i,a,b)      for(int i=a;i>=b;i--)
#define TEST_CASE(t)     for(int z=1;z<=t;z++)
#define PRINT_CASE       printf("Case %d:\n",z)
#define CASE_PRINT       cout<<"Case "<<z<<": "
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1<<28)
#define ull              unsigned long long
#define gcd(a, b)        __gcd(a, b)
#define lcm(a, b)        ((a)*((b)/gcd(a,b)))

using namespace std;

/*----------------------Graph Moves----------------*/
//const int fx[]={+1,-1,+0,+0};
//const int fy[]={+0,+0,+1,-1};
//const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1};   // Kings Move
//const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1};  // Kings Move
//const int fx[]={-2, -2, -1, -1,  1,  1,  2,  2};  // Knights Move
//const int fy[]={-1,  1, -2,  2, -2,  2, -1,  1}; // Knights Move
/*------------------------------------------------*/

//int Set(int N,int pos){return N=N | (1<<pos);}
//int reset(int N,int pos){return N= N & ~(1<<pos);}
//bool check(int N,int pos){return (bool)(N & (1<<pos));}
/*------------------------------------------------*/

int n,q;

int par[100005];
ll dis[100005];

int sparse_par[100005][20];

void build_talbe()
{
ms(sparse_par,-1);
for(int i=0; i<n; i++)
{
sparse_par[i][0]=par[i];
}

for(int j=1; 1<<j <n; j++)
{
for(int i=0; i<n; i++)
{
sparse_par[i][j]=sparse_par[sparse_par[i][j-1]][j-1];
}
}
}

ll query(int p, ll v)
{

int log=log2(n);

for(int i=log; i>=0; i--)
{

//        int a=sparse_par[p][i];
//        int b=dis[sparse_par[p][i]];

if(dis[sparse_par[p][i]]>=v)
{
p=sparse_par[p][i];
}
}

return p;

}

int main()
{

//    freopen("in.txt","r",stdin);
///freopen("out.txt","w",stdout);

int t;
sf(t);

TEST_CASE(t)
{
sff(n,q);

par[0]=0;
dis[0]=1;

loop1(i,n-1)
{
ll a,b;
sffl(a,b);
par[i]=a;
dis[i]=b;
}

build_talbe();

PRINT_CASE;

while(q--)
{
ll a,b;
sffl(a,b);
printf("%d\n",query(a,b));
}

}

return 0;
}

```