Cod sursa(job #2846352)

Utilizator AswVwsACamburu Luca AswVwsA Data 9 februarie 2022 10:12:54
Problema Oite Scor 80
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.85 kb
#include <fstream>
#include <algorithm>
#include <unordered_map>
#include <vector>
using namespace std;

const int NMAX = 1024, MOD = 604801;
int v[NMAX + 3];

vector <pair <int, int> > r[MOD];
int main()
{
    ifstream cin("oite.in");
    ofstream cout("oite.out");
    int n, s, i, j;
    cin >> n >> s;
    for (i = 1; i <= n; i++)
        cin >> v[i];
    int ans = 0;
    for (i = 1; i + 1 <= n; i++)
        for (j = i + 1; j <= n; j++)
        {
            int sum = v[i] + v[j];
            r[sum % MOD].push_back({v[i] + v[j], j});
            int need = s - sum;
            if (need < 0)
                continue;
            int val = need % MOD;
            for (int k = 0; k < r[val].size(); k++)
                if (r[val][k].first == need and r[val][k].second < i)
                    ans++;
        }
    cout << ans;
}