Submission #1143707

#	Time	Username	Problem	Language	Result	Execution time	Memory
1143707		Agageldi	XOR Sum (info1cup17_xorsum)	C++20	7 / 100	1695 ms	19648 KiB

xorsum

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

#define ll long long
#define N 6000005
#define pb push_back
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define sz(s) (int)s.size()

ll T, n, a[N], ans = 0;
map <ll,ll> vis, vip;
vector <ll> v1, v0;

int main () {
	cin >> n;
	for(int i = 1;i <= n; i++){
		cin >> a[i];
	}
	sort(a+1,a+n+1);
	for(int i = 0;i <= 30; i++) {
		v1.clear();
		v0.clear();
		for(int j = 1; j <= n; j++) {
			if((a[j] &(1 << i)))v1.pb(a[j] % (1 << i));
			else v0.pb(a[j] % (1LL << i));
		}
		int cnt = 0;
		for(int j = 0; j < sz(v1); j++) {
			for(int k = 0; k < sz(v0); k++) {
				if((v1[j] + v0[k]) < (1 << i)) cnt++;
			}
		}
		for(int j = 0; j < sz(v0); j++) {
			for(int k = j; k < sz(v0); k++) {
				if((v0[j] + v0[k]) >= (1<<i)) cnt++;
			}
		}
		for(int j = 0;j < sz(v1);j++) {
			for(int k = j; k < sz(v1); k++) {
				if((v1[j] + v1[k]) >= (1 << i)) cnt++;
			}
		}
		if(cnt%2) {
			ans |= (1<<i);
		}		
	}
	cout << ans << '\n';
}

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