Cod sursa(job #2522366)
Utilizator | Burca Olivia olivia.29 | Data | 12 ianuarie 2020 14:17:13 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 0 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.53 kb |
#include <fstream>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int main()
{
int st,dr,n,m,v[801],k=0,s,p;
fin>>n;
for(int i=1;i<=n;i++)
fin>>v[i];
for(int i=1;i<=n;i++)
for(int j=i+1;j<=n;j++)
{
p=0;
s=v[i]+v[j];
st=j; dr=n;
while(st<=dr)
{
m=(st+dr)/2;
if(s<v[m]) dr=m-1;
else {st=m+1; p=m;}
}
if(p) k+=p-j;
}
fout<<k;
return 0;
}