Cod sursa(job #2429932)
Utilizator | Data | 11 iunie 2019 21:07:17 | |
---|---|---|---|
Problema | Oite | Scor | 70 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva de probleme | Marime | 0.59 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("oite.in");
ofstream fout("oite.out");
int main() {
int n, s;
fin >> n >> s;
vector<int> v(n + 1);
for (int i = 1; i <= n; i++)
fin >> v[i];
int64_t sol = 0;
unordered_map<int, int> sums(n + 1);
sums[v[1] + v[2]]++;
for (int i = 3; i < n; i++) {
for (int j = i + 1; j <= n; j++)
sol += sums[s - v[i] - v[j]];
for (int j = i - 1; j >= 1; j--)
sums[v[i] + v[j]]++;
}
fout << sol << '\n';
fout.close();
return 0;
}