Submission #748601

#	Time	Username	Problem	Language	Result	Execution time	Memory
748601		Desh03	XORanges (eJOI19_xoranges)	C++17	100 / 100	122 ms	8692 KiB

xoranges

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

struct fenwick {
    vector<int> fenw;
    int n;
    fenwick(int n_) : n(n_) {
        fenw.resize(n);
    }
    void upd(int u, int x) {
        for (; u < n; u |= u + 1) fenw[u] ^= x;
    }
    int qry(int u) {
        int xr = 0;
        for (; u >= 0; u = (u & (u + 1)) - 1) xr ^= fenw[u];
        return xr;
    }
    int qry(int l, int r) {
        return qry(r) ^ qry(l - 1);
    }
};

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n, q;
    cin >> n >> q;
    vector<int> a(n);
    fenwick bit1(n), bit2(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        if (i & 1) bit2.upd(i, a[i]);
        else bit1.upd(i, a[i]);
    }
    while (q--) {
        int t, l, u;
        cin >> t >> l >> u;
        if (t == 1) {
            --l;
            if (l & 1) bit2.upd(l, u ^ a[l]);
            else bit1.upd(l, u ^ a[l]);
            a[l] = u;
        } else {
            --l, --u;
            if (u - l & 1) cout << "0\n";
            else cout << (l & 1 ? bit2.qry(l, u) : bit1.qry(l, u)) << '\n';
        }
    }
}

Compilation message (stderr)

xoranges.cpp: In function 'int main()':
xoranges.cpp:45:19: warning: suggest parentheses around '-' in operand of '&' [-Wparentheses]
   45 |             if (u - l & 1) cout << "0\n";
      |                 ~~^~~

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