Pagini recente » Cod sursa (job #3139249) | Cod sursa (job #998713) | Cod sursa (job #1618557) | Cod sursa (job #326317) | Cod sursa (job #960938)
Cod sursa(job #960938)
#include <fstream>
#include <vector>
using namespace std;
#define in "oite.in"
#define out "oite.out"
#define MOD 666013
#define N 1030
#define h(x) (x%MOD)
typedef unsigned u;
vector <int> HASH[MOD];
int v[N],n, L, sol;
int search(int x) {
int ans = 0, k = h(x);
for (u i = 0; i < HASH[k].size(); ++i)
if (HASH[k][i] == x)
ans++;
return ans;
}
int main() {
ifstream fin (in);
fin >> n >> L;
for (int i = 0; i < n; ++i)
fin >> v[i];
fin.close();
for (int i = 0; i < n - 1; ++i) {
for (int j = i + 1; j < n; ++j)
if (L - v[j] - v[i] >= 0)
sol += search (L - v[j] - v[i]);
for (int j = 0; j < i; ++j)
if (v[i] + v[j] <= L)
HASH[h (v[j] + v[i])].push_back (v[j] + v[i]);
}
ofstream fout (out);
fout << sol;
fout.close();
return 0;
}