CoderForces985F-Isomorphic Strings(字符串哈希)

#include<iostream>
#include<queue>
#include<cstdio>
#include<vector>
#include<algorithm>
using namespace std;
typedef long long ll;
const int maxn=2e5+10;
const ll MOD=1e9+7;
ll h[26][maxn],x=107,px[maxn];
char s[maxn];
int main()
{
    int n,m;
    scanf("%d%d", &n,&m);
    scanf("%s", s+1);
    px[0]=1;
    for(int i = 1; i <= n; ++i) px[i]=px[i-1]*x%MOD;
    for(int i = 0; i < 26; ++i)
	{
        for(int j = 1; j <= n; ++j) h[i][j]=(h[i][j-1]*x+int(s[j] == (i+'a')))%MOD;
    }
    while(m--)
	{
        int x,y,l;
        scanf("%d%d%d", &x,&y,&l);
        vector<int> p,q;
        for(int i = 0; i < 26; ++i)
		{
            p.push_back(((h[i][x+l-1]-px[l]*h[i][x-1]%MOD)%MOD+MOD)%MOD);
            q.push_back(((h[i][y+l-1]-px[l]*h[i][y-1]%MOD)%MOD+MOD)%MOD);
        }
        sort(q.begin(),q.end());sort(p.begin(),p.end());
        printf("%s\n", p==q? "YES":"NO");
    }
    return 0;
}