Cod sursa(job #2734738)
Utilizator | Linca Mihaela Amalia Linca_Amalia | Data | 1 aprilie 2021 12:21:05 |
---|---|---|---|
Problema | Numarare triunghiuri | Scor | 100 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.69 kb |
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("nrtri.in");
ofstream fout("nrtri.out");
int n, i, j, dr, st, mid, sol, v[1000];
int main(){
fin >> n;
for ( i = 1; i <= n; i++ )
fin >> v[i];
sort( v + 1, v + n + 1 );
for ( i = 1; i <= n; i++ ){
for ( j = i + 1; j <= n; j++ ){
st = j + 1;
dr = n;
while ( st <= dr ){
mid = ( st + dr ) / 2;
if ( v[mid] <= v[i] + v[j] )
st = mid + 1;
else
dr = mid - 1;
}
sol += dr - j;
}
}
fout << sol;
return 0;
}