Acwing 841. 字符串哈希

题目描述

思路讲解

代码展示

#include <iostream>
#include <algorithm>using namespace std;typedef unsigned long long ULL;const int N = 100010, P = 131; // P = 131 或者13331(经验值)int n, m;
char str[N];
ULL h[N], p[N];ULL get(int l, int r) {return h[r] - h[l - 1] * p[r - l + 1];
}int main() {scanf("%d%d", &n, &m);scanf("%s", str + 1);p[0] = 1;for (int i = 1; i <= n; i++) {h[i] = h[i - 1] * P + str[i];p[i] = p[i - 1] * P;}while (m--) {int l1, r1, l2, r2;scanf("%d%d%d%d", &l1, &r1, &l2, &r2);if (get(l1, r1) == get(l2, r2)) puts("Yes");else puts("No");}return 0;
}