Cod sursa(job #1949786)
Utilizator | Usurelu Florian-Robert usureluflorian | Data | 2 aprilie 2017 13:12:38 |
---|---|---|---|
Problema | Trapez | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva de probleme | Marime | 0.53 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream f ("trapez.in");
ofstream g ("trapez.out");
int n,k,i,j,s,x[1001],y[1001],nr;
double p[1000001];
int main()
{
f>>n;
for(i=1;i<=n;++i) f>>x[i]>>y[i];
for(i=1;i<=n;++i)
{
for(j=i+1;j<=n;j++)
{
p[++k]=(double)(x[i]-x[j])/(y[i]-y[j]);
}
}
sort(p+1,p+k+1);
for(i=1;i<=k;++i)
{
nr=1;
while(p[i]==p[i+1]&&i+1<=k) {++nr;++i;}
s+=(nr-1)*nr/2;
}
g<<s;
return 0;
}