Shared code

#include <bits/stdc++.h>

#define range(it, a, b) for (ll it = a; it < b; it++)
#define all(x) begin(x), end(x)
#define ll long long
#define ull unsigned long long
#define INF64 ((ll) 1 << 60)
#define INF32 (1 << 30)
#define uset unordered_set
#define umap unordered_map 
#define pqueue priority_queue

using namespace std;

void setio (string name) {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    if (name.size()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }   
}

struct XorSegmentTree  {
    struct Node {
        ll l, r, val;
        Node* next_left;
        Node* next_right;

        ll get_left() { return (l + r) / 2; }
        ll get_right() { return get_left() + 1; } 
    };

    Node* root = new Node();
    vector<ll>& arr;

    XorSegmentTree (vector<ll>& a) : arr(a) {
        root->l = 0;
        root->r = a.size() - 1;
        build_tree(root);
    }

    void build_tree (Node* node) {
        if (node->l == node->r) {
            node->val = arr[node->l];
            return;
        }

        node->next_left = new Node();
        node->next_left->l = node->l;
        node->next_left->r = node->get_left();
        build_tree(node->next_left);

        node->next_right = new Node();
        node->next_right->l = node->get_right();
        node->next_right->r = node->r;
        build_tree(node->next_right);

        node->val = node->next_left->val ^ node->next_right->val;
    }

    ll _get(ll l, ll r, Node* node) {
        if (node->l == l && node->r == r) 
            return node->val;
        
        ll r1 = (l <= node->get_left() ? _get(l, min(node->get_left(), r), node->next_left) : 0);
        ll r2 = (r >= node->get_right() ? _get(max(node->get_right(), l), r, node->next_right) : 0);
        return r1 ^ r2;
    }

    ll get(ll l, ll r) {
        return _get(l, r, root);
    }
};

ll n, q;
vector<ll> a;

void solve() {
    cin >> n >> q;
    a.resize(n);
    range(i, 0, n) cin >> a[i];
    XorSegmentTree st (a);

    ll l, r;
    while (q--) {
        cin >> l >> r;
        l--; r--;
        cout << st.get(l, r) << '\n';
    }
}

int main () {
    setio("");
    ll t = 1; 
    // cin >> t;
    while (t--) solve();
}