Submission #1246300

#	Time	Username	Problem	Language	Result	Execution time	Memory
1246300		wedonttalkanymore	XORanges (eJOI19_xoranges)	C++20	100 / 100	142 ms	15700 KiB

xoranges

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

#define int long long

const ll N = 2e5 + 5;
int n, q;
int a[N];

struct ST {
    vector<int> st;
    ST(int _n) { st.assign(4 * _n, 0); }
    void update(int i, int l, int r, int pos, int val) {
        if (l == r) {
            st[i] = val;
            return;
        }
        int mid = (l + r) / 2;
        if (pos <= mid) update(2 * i, l, mid, pos, val);
        else update(2 * i + 1, mid + 1, r, pos, val);
        st[i] = st[2 * i] ^ st[2 * i + 1];
    }
    int get(int i, int l, int r, int u, int v) {
        if (u > r || v < l) return 0;
        if (u <= l && r <= v) return st[i];
        int mid = (l + r) / 2;
        return get(2 * i, l, mid, u, v) ^ get(2 * i + 1, mid + 1, r, u, v);
    }
};

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n >> q;
    for (int i = 1; i <= n; i++) cin >> a[i];

    ST st_even(n), st_odd(n);
    for (int i = 1; i <= n; i++) {
        if (i % 2 == 0) st_even.update(1, 1, n, i, a[i]);
        else st_odd.update(1, 1, n, i, a[i]);
    }

    while (q--) {
        int type, l, r;
        cin >> type >> l >> r;
        if (type == 1) {
            a[l] = r;
            if (l % 2 == 0) st_even.update(1, 1, n, l, r);
            else st_odd.update(1, 1, n, l, r);
        } else {
            int len = r - l + 1;
            if (len % 2 == 0) {
                cout << 0 << '\n';
            } else {
                if (l % 2 == 0)
                    cout << st_even.get(1, 1, n, l, r) << '\n';
                else
                    cout << st_odd.get(1, 1, n, l, r) << '\n';
            }
        }
    }
    return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 25 / 25
• Subtask 4: 20 / 20
• Subtask 5: 25 / 25