Cod sursa(job #652248)

Utilizator d.andreiDiaconeasa Andrei d.andrei Data 23 decembrie 2011 17:04:39
Problema Oite Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.18 kb
#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

#define file_in "oite.in"
#define file_out "oite.out"

#define nmax (1<<10)
#define mod 666013

int N,S,M,V[nmax+10],i,ans=0,j;
vector<int> H[mod];

void inserare(int value){
	
	int key=value%mod;
	
	H[key].push_back(value);
}


int cauta(int value){
	
	int key=value%mod;
	int nr=0;
	vector<int> :: iterator it;
	
	for (it=H[key].begin();it!=H[key].end();++it)
		 if (*it==value)
			 nr++;
	return nr;
}

void sterge(int value){
	
	int key=value%mod;
	vector<int> :: iterator it;
	
	for (it=H[key].begin();it!=H[key].end();++it)
		 if (*it==value){
			  H[key].erase(it);
			  return;
		 }
}

int main(){
	
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d", &N, &S);
	for (i=1;i<=N;++i)
		 scanf("%d", &V[i]);
	
	sort(V+1,V+N+1);
	
	M=0;
	for (i=3;i<=N;++i)
		 for (j=i+1;j<=N;++j)
			  inserare(V[i]+V[j]);
	
	//sort(H+1,H+M+1);

    for (j=2;j<=N-2;++j){
         for (i=1;i<j;++i)
              ans+=cauta(S-V[i]-V[j]);
		 for (i=j+2;i<=N;++i)
			  sterge(V[j+1]+V[i]);
	}
			 

	printf("%d\n", ans);

	return 0;

}