Xor sum

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

using ll=long long;
using vl=vector<ll>;
#define all(c) begin(c),end(c)
#define pb push_back
#define sz(c) ll((c).size())

#define FOR(i,a,b) for(ll i=(a);i<(b);i++)

#define TR(x) ({ if(1) cout << __LINE__ << ": " #x " = " << (x) << endl; })

// Only when needed
using dd = double;
const dd eps = 1e-10;
using vd = vector<dd>;
using vvd = vector<vd>;
using vvl = vector<vl>;

void solve(){
	ll n, q; cin >> n >> q;
	vl a(n), pref(n + 1);
	for(ll &x : a) cin >> x;
	FOR(i, 0, n){
		pref[i + 1] = pref[i] ^ a[i];
	}
	FOR(i, 0, q){
		ll a, b; cin >> a >> b;
		a--;
		cout << (pref[b] ^ pref[a]) << "\n";
	}
}

int main() {
	cin.tie(0)->sync_with_stdio(0);
	 solve();
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED