제출 #141164

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
141164		meatrow	XOR Sum (info1cup17_xorsum)	C++17	0 / 100	1701 ms	15992 KiB

xorsum

//#pragma GCC optimize("O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
//#pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;

const int M = 20;
const int N = 3e6;

int a[N];
int f[N];

void add(int pos) {
    for (; pos < N; pos |= pos + 1) {
        f[pos]++;
    }
}

int get(int pos) {
    int res = 0;
    for (; pos >= 0; pos = (pos & (pos + 1)) - 1) {
        res += f[pos];
    }
    return res;
}

int get(int l, int r) {
    if (l > r) {
        return 0;
    }
    return get(r) - get(l - 1);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int n;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    int ans = 0;
    int pw = 2;
    for (int b = 0; b < M; b++) {
        fill(f, f + N, 0);
        int kek = 0;
        for (int i = 0; i < n; i++) {
            int t = a[i] & (pw - 1);
            add(t);
            if (a[i] & (1 << b)) {
                kek += get(0, pw - 1 - t)
                       + get(pw - t + pw / 2, pw - 1);
                kek &= 1;
            } else {
                kek += get(pw / 2 - t, pw - 1 - t);
                kek &= 1;
            }
        }
        if (kek) {
            ans += pw >> 1;
        }
        pw <<= 1;
    }
    cout << ans;
    return 0;
}

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