Submission #1246298

#	Time	Username	Problem	Language	Result	Execution time	Memory
1246298		wedonttalkanymore	XORanges (eJOI19_xoranges)	C++20	0 / 100	145 ms	16440 KiB

xoranges

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

#define int long long
#define pii pair<ll, ll>
#define fi first
#define se second

const ll N = 2e5 + 5, inf = 1e18, mod = 1e9 + 7, block = 320, lim = 1 << 16;

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(0);
    if (fopen(".inp", "r")) {
        freopen(".inp", "r", stdin);
        freopen(".out", "w", stdout);
    }
    cin >> n >> q;
    for (int i = 1; i <= n; i++) cin >> a[i];
    ST st1(n + 1), st2(n + 1);
    for (int i = 1; i <= n; i++) {
        if (i % 2 == 0) st1.update(1, 1, n, i, a[i]);
        else st2.update(1, 1, n, i, a[i]);
    }
    while(q-- > 0) {
        int type, l, r;
        cin >> type >> l >> r;
        if (type == 1) {
            if (l % 2 == 0) st1.update(1, 1, n, l, r);
            else st2.update(1, 1, n, l, r);
        }
        else {
            if ((r - l + 1) % 2 == 0) cout << 0;
            if (l % 2 == 0) cout << st1.get(1, 1, n, l, r) << '\n';
            else cout << st2.get(1, 1, n, l, r) << '\n';
        }
    }
    return 0;
}

Compilation message (stderr)

xoranges.cpp: In function 'int main()':
xoranges.cpp:41:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   41 |         freopen(".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~
xoranges.cpp:42:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |         freopen(".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 18
• Subtask 3: 0 / 25
• Subtask 4: 0 / 20
• Subtask 5: 0 / 25