제출 #1148285

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1148285		weakweakweak	XOR Sum (info1cup17_xorsum)	C++20	0 / 100	1663 ms	121892 KiB

xorsum

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

int n, a[1888888], tmp[1999999][3];
vector<int> v[31];

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        for (int j = 0; j < 30; j++) {
            v[j].push_back(a[i]%(1<<(j+1)));
        }
    }

    int ans = 0;
    for (int b = 0; b < 30; b++) {
        sort(v[b].begin(), v[b].end());
        int cnt = 0;
        for (int i = 0, j=n, j2=n, j3=n; i < n; i++) {
            while (j > 0 and v[b][i] + v[b][j-1] >= (1<<b)) j--;
            while (j2 > 0 and v[b][i] + v[b][j2-1] >= (1<<(b+1))) j2--;
            while (j3 > 0 and v[b][i] + v[b][j3-1] >= (1<<b)+(1<<(b+1))) j3--;
            int a1 = n - j, a2 = n - j2, a3 = n - j3;
            cnt += (a1-a2)&1;
            cnt += (a3)&1;
        }
        if (cnt & 1) ans += (1<<b);
    }
    cout << ans << '\n';
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 38
• Subtask 5: 0 / 23