Xor sum

#include <bits/stdc++.h> 
using namespace std;

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    vector<int> tree(2 * n);
    for (int i = 0; i < n; i++) {
        cin >> tree[n + i];
    }
    for (int i = n-1; i > 0; --i) {
        tree[i] = tree[2 * i]^tree[2 * i + 1];
    }

    for (int i =0; i<q; i++){
        int a;
        int b;
        cin>>a>>b;
        a--;b--;
        a += n; b += n;
        int s = 0;
        while (a <= b) {
        if (a%2 == 1) s = s^tree[a++];
        if (b%2 == 0) s = s^tree[b--];
        a /= 2; b /= 2;
        }
        cout<<s<<"\n";
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED