제출 #272190

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
272190		theStaticMind	XOR Sum (info1cup17_xorsum)	C++14	0 / 100	180 ms	131076 KiB

xorsum

#include<bits/stdc++.h>
#define pb push_back
#define ii pair<int,int>
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define INF 100000000000000000
#define modulo 1000000007
#define mod 998244353
#define int long long int
using namespace std;

int32_t main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	freopen("q.gir", "r", stdin);
	freopen("q.cik", "w", stdout);

	int n, ans = 0;
	cin >> n;
	vector<int> arr(n);
	vector<ii> A;

	for(int i = 0; i < n; i++) cin >> arr[i], A.pb({0, i});

	for(int d = 0; d < 50; d++){
		int w = (1ll << d);
		vector<ii> t0, t1;
		for(auto p : A){
			if(arr[p.second] & w) t1.pb({arr[p.second] % (w * 2), p.second});
			else t0.pb({arr[p.second] % (w * 2), p.second});
		}

		A = t0;
		for(auto p : t1) A.pb(p);

		int p1 = n - 1, p2 = n - 1, p3 = n - 1, cnt = 0;

		for(auto p : A){
			while(p1 >= 0 && A[p1].first + p.first >= w) p1--;
			while(p2 >= 0 && A[p2].first + p.first >= w * 2) p2--;
			while(p3 >= 0 && A[p3].first + p.first >= w * 3) p3--;

			cnt += n - 1 - p3 + p2 - p1;
		}

		for(auto p : A){
			if((p.first * 2) & w) cnt++;
		}

		assert(cnt % 2 == 0);
		cnt /= 2;
		if(cnt % 2) ans |= w;
	}
	cout << ans;
}

컴파일 시 표준 에러 (stderr) 메시지

xorsum.cpp: In function 'int32_t main()':
xorsum.cpp:16:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   16 |  freopen("q.gir", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
xorsum.cpp:17:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   17 |  freopen("q.cik", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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