제출 #37257

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
37257		Yusup01	별들과 삼각형 (IZhO11_triangle)	C++14	0 / 100	0 ms	6868 KiB

triangle

#include<bits/stdc++.h>
using namespace std;
long long x[300009],y[300009],jog;
int n;
map<long long,int> X,Y;
int main()
{
	ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	freopen("triangle.in","r",stdin);
	freopen("triangle.out","w",stdout);
	cin>>n;
	for(int i=1;i<=n;i++){cin>>x[i]>>y[i]; X[x[i]]++; Y[y[i]]++;}
	for(int i=1;i<=n;i++)
	{
		jog+=(X[x[i]]-1)*(Y[y[i]]-1);
	}
	cout<<jog;
}

컴파일 시 표준 에러 (stderr) 메시지

triangle.cpp: In function 'int main()':
triangle.cpp:9:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("triangle.in","r",stdin);
                                  ^
triangle.cpp:10:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("triangle.out","w",stdout);
                                    ^

• Subtask 1: 0 / 100