思想

可以抽象为将字符串转换成P进制的数

算法1

C++ 代码

#include<iostream>
#include<string>

using namespace std;
typedef unsigned long long ULL;
const int N = 1e5 + 5,P = 131;
ULL h[N],p[N];

ULL query(int l,int r){
    return h[r] - h[l - 1] * p[r - l + 1];
}

int main(){
    int n,m;
    cin >> n >> m;
    string x;
    cin >> x;

    p[0] = 1;
    h[0] = 0;
    for(int i = 0; i < n; i ++){
        p[i + 1] = p[i] * P;
        h[i + 1] = h[i] * P + x[i];
    }

    while(m --){
        int l1,r1,l2,r2;
        cin >> l1 >> r1 >> l2 >> r2;
        if(query(l1,r1) == query(l2,r2)) printf("Yes\n");
        else printf("No\n");
    }
    return 0;
}