Xor sum

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

#define all(x)  begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x)   (int)(x).size()                                 // signed size: avoids the unsigned .size() wrap bug

using ll  = long long;
using pii = pair<int,int>;
using vi  = vector<int>;

#ifdef LOCAL                                                    // compile with -DLOCAL to enable, silent on the judge
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "] = ", dbg_out(__VA_ARGS__)
template<class T> void dbg_out(T x) { cerr << x << '\n'; }
template<class T, class... R> void dbg_out(T x, R... r) { cerr << x << ", "; dbg_out(r...); }
#else
#define dbg(...)
#endif

int main() {
    cin.tie(0)->sync_with_stdio(0);                             // never mix with scanf/printf after this
    // int n; cin >> n; 
    int n,q; cin >> n >> q; 
    vi a(n); for (auto &x : a) cin >> x;

    vi cum(n+1);
    int current = 0;

    for (int i = 0; i < n+1; i++)
    {
        cum[i] = current;
        // cout << current << "\n";
        current  = current ^ a[i];
    }
    int c,b;
    
    for (int i = 0; i < q; i++)
    {
        cin >> c >> b;
        int out = cum[c-1] ^ cum[b+1-1];
        // int out = (int) 2 ^ 4 ^ 5 ;
        // cout << cum[c-1] << "  " << cum[b+1-1] << "  ";
        cout << out << "\n";



    }








    // cout << ;
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED