Xor sum

#include <bits/stdc++.h>

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

    long n, q;
    std::cin >> n >> q;

    std::vector<long long> sum(n + 1, 0);
    std::cin >> sum[1];
    for (long i = 2; i <= n; i++) {
        long a;
        std::cin >> a;
        sum[i] = sum[i-1] ^ a;
    }

    for (long i = 0; i < q; i++) {
        long a,b;
        std::cin >> a >> b;
        std::cout << (sum[a-1] ^ sum[b]) << std::endl;
    }

    std::cout << std::endl;
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED