# UVa 10679 – I Love Strings!!

Solution Idea: Build Suffix Array then binary search on the sorted sequence.

```
#include &lt;bits/stdc++.h&gt;

#define pii              pair &lt;int,int&gt;
#define pll              pair &lt;long long,long long&gt;
#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&lt;&lt;#x &quot; = &quot;&lt;&lt;(x)&lt;&lt;endl
#define VI               vector &lt;int&gt;
#define DBG              pf(&quot;Hi\n&quot;)
#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(&quot;%d&quot;,&amp;a)
#define sfl(a)           scanf(&quot;%lld&quot;,&amp;a)
#define sff(a,b)         scanf(&quot;%d %d&quot;,&amp;a,&amp;b)
#define sffl(a,b)        scanf(&quot;%lld %lld&quot;,&amp;a,&amp;b)
#define sfff(a,b,c)      scanf(&quot;%d %d %d&quot;,&amp;a,&amp;b,&amp;c)
#define sfffl(a,b,c)     scanf(&quot;%lld %lld %lld&quot;,&amp;a,&amp;b,&amp;c)
#define stlloop(v)       for(__typeof(v.begin()) it=v.begin();it!=v.end();it++)
#define loop(i,n)        for(int i=0;i&lt;n;i++)
#define loop1(i,n)       for(int i=1;i&lt;=n;i++)
#define REP(i,a,b)       for(int i=a;i&lt;b;i++)
#define RREP(i,a,b)      for(int i=a;i&gt;=b;i--)
#define TEST_CASE(t)     for(int z=1;z&lt;=t;z++)
#define PRINT_CASE       printf(&quot;Case %d: &quot;,z)
#define LINE_PRINT_CASE  printf(&quot;Case %d:\n&quot;,z)
#define CASE_PRINT       cout&lt;&lt;&quot;Case &quot;&lt;&lt;z&lt;&lt;&quot;: &quot;
#define all(a)           a.begin(),a.end()
#define intlim           2147483648
#define infinity         (1&lt;&lt;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&lt;&lt;pos);}
//int reset(int N,int pos){return N= N &amp; ~(1&lt;&lt;pos);}
//bool check(int N,int pos){return (bool)(N &amp; (1&lt;&lt;pos));}
/*------------------------------------------------*/

#define mx 100005

int suffix_array[mx],position[mx];

struct data
{
pii rank;
int pos;
};

bool cmp(data a, data b)
{
return a.rank&lt;b.rank;
}

char str[mx],query[mx];

int main()
{

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

int t;
sf(t);
TEST_CASE(t)
{
scanf(&quot;%s&quot;,str);

int n=strlen(str);

for(int i=0;i&lt;n;i++) position[i]=str[i];

for(int k=1;k&lt;n;k*=2)
{
vector&lt;data&gt;v(n);
for(int i=0;i&lt;n;i++)
{
int a=position[i];
int b;
if(i+k&gt;=n)
b=-1;
else
b=position[i+k];
v[i].rank=pii(a,b);
v[i].pos=i;
}

sort(all(v),cmp);

position[v[0].pos]=0;
suffix_array[0]=v[0].pos;
for(int i=1;i&lt;n;i++)
{
suffix_array[i]=v[i].pos;
if(v[i].rank==v[i-1].rank)
position[v[i].pos]=position[v[i-1].pos];
else
position[v[i].pos]=i;
}
}

int q;
sf(q);
while(q--)
{
scanf(&quot;%s&quot;,query);
int l=strlen(query);
int lo=0,hi=n-1;
bool ans=0;
while(lo&lt;=hi)
{
int mid=(lo+hi)/2;
int x=strncmp(str+suffix_array[mid],query,l);
if(x==0)
{
ans=1;
break;
}
else if(x&gt;0)
hi=mid-1;
else
lo=mid+1;
}
if(ans)
pf(&quot;y\n&quot;);
else
pf(&quot;n\n&quot;);
}
}

return 0;
}

```