O(1)查询

int P = 131; //或者13331
char str[100005];
ull h[100005], p[100005];

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

int main()
{
    int n, m;
    cin >> n >> m >> str + 1;
    p[0] = 1;
    for (int i = 1; i <= n; i++)//计算子串str[l ~ r]的哈希值
    {
        p[i] = p[i - 1] * P;
        h[i] = h[i - 1] * P + str[i];
    }
    while (m--)
    {
        int l1, r1, l2, r2;
        cin >> l1 >> r1 >> l2 >> r2;
        if (get(l1, r1) == get(l2, r2))//比较子串str[l1 ~ r1]的哈希值与子串str[l2 ~ r2]的哈希值是否一致
        {
            cout << "Yes" << endl;
        }
        else
        {
            cout << "No" << endl;
        }
    }
    return 0;
}