Xor sum

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
 
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    vector<long long> arr(n);
    for(auto &x: arr) cin >> x;
    vector<long long> prefix(n+1, 0);
    for(int i=1; i<=n; ++i){
        prefix[i] = prefix[i-1] ^ arr[i-1];
    }
    while(q--){
        int a, b;
        cin >> a >> b;
        cout << (prefix[b] ^ prefix[a-1]) << "\n";
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED