Xor sum

#include <iostream>
#include <vector>

using namespace std;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, q;
    cin >> n >> q;

    vector<int> pref(n + 1, 0);

    for (int i = 1; i <= n; ++i) {
        int x;
        cin >> x;
        pref[i] = pref[i - 1] ^ x;
    }

    while (q--) {
        int a, b;
        cin >> a >> b;
        cout << (pref[b] ^ pref[a - 1]) << endl;
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED