Submission #87935

#	Time	Username	Problem	Language	Result	Execution time	Memory
87935		turbat	Star triangles (IZhO11_triangle)	C++14	0 / 100	2 ms	376 KiB

triangle

/* 
ID: turbat_1
TASK: sort3
LANG: C++
*/
#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
int n;
long long ans;
pair <int, int> p[300005];
map <int, int> my, mx;

int main (){
	freopen("triangles.in", "r",  stdin);
	freopen("triangles.out", "w", stdout);
	cin >> n;
	for (int i = 0;i < n;i++){
		cin >> p[i].F>> p[i].S;
		mx[p[i].F]++;
		my[p[i].S]++;
	}
	for (int i = 0;i < n;i++)
		ans += (mx[p[i].F] - 1) * (my[p[i].S] - 1);
	cout << ans<<endl;
}

Compilation message (stderr)

triangle.cpp: In function 'int main()':
triangle.cpp:16:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("triangles.in", "r",  stdin);
  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
triangle.cpp:17:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("triangles.out", "w", stdout);
  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 100