Cod sursa(job #248482)

Utilizator andrei-alphaAndrei-Bogdan Antonescu andrei-alpha Data 25 ianuarie 2009 21:10:22
Problema Oite Scor 90
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.53 kb
using namespace std;

#include <set>
#include <map>
#include <list>
#include <deque>
#include <stack>
#include <queue>
#include <cmath>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cstdlib>
#include <utility>
#include <algorithm>
#include <functional>
#include <ext/hash_set>   

#define pb push_back
#define sz size
#define f first
#define s second
#define II inline
#define ll long long
#define db double
#define FOR(i,a,b) for(int i=a;i<=b;++i)
#define all(v) v.begin() , v.end()
#define C(v) memset((v),0,sizeof((v)))
#define CP(x,y) memcpy((x),(y),sizeof((y)))
#define FORit(it,v) for(it = (v).begin();it != (v).end();++it)
#define mp make_pair

#define IN  "oite.in"
#define OUT "oite.out"
#define N_MAX 1<<10
#define ui unsigned int
#define mod 65535

int N,V[N_MAX];
ui rez,S;
vector< vector<int> > A(mod+4);

II void scan()
{
	freopen(IN,"r",stdin);
	freopen(OUT,"w",stdout);
	scanf("%u%u",&N,&S);
	
	FOR(i,1,N)
		scanf("%u",&V[i]);
	sort(V+1,V+N+1);	
}

II int count(int x)
{
	int rest = x & mod;
	int cat = x / mod;
	int count(0);
	FOR(i,0,(int)A[rest].sz()-1)  
        if(A[rest][i] == cat)  
			++count;  
    return count; 
}

II void insert(int x)
{
	A[x&mod].pb(x/mod);
}

II void solve()
{
	for(int i=N-2;i>=1;--i)
	{
		int SS = V[i+1];
		FOR(j,i+2,N)
			insert(SS + V[j]);
		SS = S - V[i];
		FOR(j,1,i-1)
			if(SS > V[j])
				rez += count(SS - V[j]);
	}	
	printf("%d\n",rez);
}

int main()
{
	scan();
	solve();
	return 0;
}