Cod sursa(job #657548)

Utilizator repp4raduRadu-Andrei Szasz repp4radu Data 6 ianuarie 2012 18:55:02
Problema Semne Scor 95
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.76 kb
#include <cstdio>
#include <vector>
#include <cstdlib>

#define MAX 50001

using namespace std;

vector<int> plus, minus;
int semn[MAX];
//semn = 1 pt plus
//semn = 0 pt minus
long long suma;
long long sumaPartiala;

int n;
int v[MAX];

void citire()
{
    freopen("semne.in", "r", stdin);
    scanf("%d %lld", &n, &suma);
    for(int i = 1; i <= n; i++)
    {
        scanf("%d", &v[i]);
    }
    fclose(stdin);
}

void firstAssignment()
{
    for(int i = 1; i <= n; i++)
    {
        if(sumaPartiala + v[i] > suma)
        {
            sumaPartiala -= v[i];
            semn[i] = 0;
            minus.push_back(i);
        }
        else
        {
            sumaPartiala += v[i];
            semn[i] = 1;
            plus.push_back(i);
        }
    }
}

void lowerSum()
{
    int which = rand() % plus.size();
    sumaPartiala -= (2 * v[plus[which]]);
    minus.push_back(plus[which]);
    semn[plus[which]] = 0;
    plus[which] = plus[plus.size() - 1];
    plus.pop_back();
}

void higherSum()
{
    int which = rand() % minus.size();
    sumaPartiala += (2 * v[minus[which]]);
    plus.push_back(minus[which]);
    semn[minus[which]] = 1;
    minus[which] = minus[minus.size() - 1];
    minus.pop_back();
}

void afisare()
{
    freopen("semne.out", "w", stdout);
    for(int i = 1; i <= n; i++)
    {
        if(semn[i])
        {
            printf("+");
        }
        else
            printf("-");
    }
    fclose(stdout);
}

int main()
{
    citire();
    firstAssignment();
    while(suma != sumaPartiala)
    {
        if(sumaPartiala > suma)
        {
            lowerSum();
        }
        else
        {
            higherSum();
        }
    }
    afisare();
    return 0;
}