Problem Link : https://www.codechef.com/problems/DIVMAC
Solution Idea:
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In this problem, a tricky observation is the primary key of the solution. That observation is the input number is in range 1 to 10^6. So We can perform update operation on an index at most 20 times. Because if we divide a number of range 1 to 10^6 with it’s prime divisors we can divide them at most 20 times.
So in the update section of segment tree we can make a check whether the maximum least prime divisor of this sub tree is 1 or not. If it is a 1 then we don’t need to update in the sub tree. Otherwise we will explore this sub tree and update them.
After this observation this problem is a simple RMQ problem.
#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #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) cerr<<#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; //using namespace __gnu_pbds; //typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; /*----------------------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 /*------------------------------------------------*/ /*-----------------------Bitmask------------------*/ //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 #define segment_tree int l=n*2,r=l+1,mid=(b+e)/2 bitset<mx/2>vis; vector<int>prime; void sieve() { int x=mx/2,y=sqrt(mx)/2; for(int i=1; i<y; i++) { if(vis[i]) { for(int j=i*(i+1)*2; j<x; j+=(2*i+1)) vis[j]=1; } } prime.pb(2); for(int i=3; i<mx; i+=2) if(vis[i/2]==0) prime.pb(i); } deque<int>dq[mx]; int tree[3*mx]; void init(int n, int b, int e) { if(b==e) { tree[n]=dq[b].front(); return; } segment_tree; init(l,b,mid); init(r,mid+1,e); tree[n]=max(tree[l],tree[r]); } void update(int n, int b, int e, int i, int j) { if(b>j || e<i) return; if(tree[n]==1) return; if(b==e) { dq[b].pop_front(); tree[n]=dq[b].front(); return; } segment_tree; update(l,b,mid,i,j); update(r,mid+1,e,i,j); tree[n]=max(tree[l],tree[r]); } int query(int n, int b, int e, int i, int j) { if(b>j || e<i) return 0; if(b>=i && e<=j) return tree[n]; segment_tree; int p=query(l,b,mid,i,j); int q=query(r,mid+1,e,i,j); return max(p,q); } int main() { // freopen("in.txt","r",stdin); // freopen("out.txt","w",stdout); sieve(); // for(int i=0;i<100;i++) // D(prime[i]); int t; sf(t); TEST_CASE(t) { int n,m; sff(n,m); for(int i=1; i<=n; i++) { int a; sf(a); int root=sqrt(a); dq[i].clear(); for(int j=0;prime[j]<=root;j++) { if(a%prime[j]==0) { while(a%prime[j]==0) { dq[i].pb(prime[j]); a/=prime[j]; } root=sqrt(a); } } if(a>1) dq[i].pb(a); dq[i].pb(1); } init(1,1,n); bool check=0; while(m--) { int a,b,c; sfff(a,b,c); if(a==0) { update(1,1,n,b,c); } else { if(check==0) { printf("%d",query(1,1,n,b,c)); check=1; } else printf(" %d",query(1,1,n,b,c)); } } printf("\n"); } return 0; }