S4: Сравнения подстрок

#include <fstream>
#include <string>
#include <vector>

using namespace std;

typedef unsigned long long ull;

int n;
const int P = 239017;

string s;
vector<ull> h, deg;

void init() {
    int n = s.length();
    deg[0] = 1, h[0] = 0;
    for (int i = 0; i < n; i++) {
        h[i + 1] = h[i] * P + s[i];
        deg[i + 1] = deg[i] * P;
    }
}

ull getHash(int i, int len) {
    return h[i + len] - h[i] * deg[len];
}

int main() {
    ifstream cin("input.txt");
    ofstream cout("output.txt");
    cin >> s;
    s += " ";
    n = s.length();
    h.resize(n + 1);
    deg.resize(n + 1);
    init();

    int m;
    string answer;
    cin >> m;
    for (int i = 0; i < m; i++) {
        int l1, r1, l2, r2;
        cin >> l1 >> r1 >> l2 >> r2;
        if (r1 - l1 != r2 - l2) {
            answer += "No\n";
        } else if (l1 == l2 and r1 == r2) {
            answer += "Yes\n";
        } else {
            l1--;
            l2--;
            if (getHash(l1, r1 - l1) != getHash(l2, r2 - l2)) {
                answer += "No\n";
            } else
                answer += "Yes\n";
        }
    }
    cout << answer;

}