Cod sursa(job #906519)

Utilizator sebii_cSebastian Claici sebii_c Data 6 martie 2013 21:33:36
Problema Semne Scor 55
Compilator cpp Status done
Runda Lista lui wefgef Marime 0.8 kb
#include <cstdio>

const int MAXN = 50001;

int S, N;
int A[MAXN];

char res[MAXN];

bool doit(long long sum, int pos)
{
    if (sum < S || (pos < 0 && sum != S))
        return false;
    if (sum == S)
        return true;

    for (int i = pos; i >= 0; --i) {
        if (sum - 2 * A[i] >= S) {
            res[i] = '-';
            if (doit(sum - 2 * A[i], i - 1))
                return true;
            res[i] = '+';
        }
    }
}

int main()
{
    freopen("semne.in", "r", stdin);
    freopen("semne.out", "w", stdout);

    scanf("%d %d", &N, &S);

    long long sum = 0;
    for (int i = 0; i < N; ++i) {
        scanf("%d", &A[i]);
        sum += A[i];
        res[i] = '+';
    }

    doit(sum, N - 1);
    for (int i = 0; i < N; ++i)
        printf("%c", res[i]);
    printf("\n");

    return 0;
}