UVAlive - 4794—— Sharing Chocolate

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std; 

int a[105];
int area[1<<16];
int dp[1<<16][105];


int bitCount(int S)
{
    int ret = 0;
    while(S) {
        if(S&1)    ret++;
        S >>= 1;
    }    
    return ret;
}

bool dfs(int S, int x)
{
    if(dp[S][x] != -1)    return dp[S][x];
    
    if(bitCount(S)==1)    return dp[S][x]=1;
    
    int y = area[S] / x;
    
    for(int S0=(S-1)&S; S0; S0=(S0-1)&S) {
        int S1 = S-S0;
        if(area[S0]%x==0 && dfs(S0, min(x, area[S0]/x)) && dfs(S1, min(x, area[S1]/x)))
            return dp[S][x]=1;
        if(area[S0]%y==0 && dfs(S0, min(y, area[S0]/y)) && dfs(S1, min(y, area[S1]/y)))
            return dp[S][x]=1;
    }
    return dp[S][x]=0;
}

int main ()
{
    int n, x, y, S, kase=1;
    while(scanf("%d", &n) != EOF && n)
    {
        scanf("%d%d", &x, &y);
        S = 0;
        for(int i=0; i<n; i++) {
            scanf("%d", &a[i]);
            S += a[i];
        }
        int ALL = (1<<n)-1;
        for(int i=0; i<=ALL; i++) {
            area[i] = 0;
            int temp = i, cur=0;
            while(temp) {
                if(temp&1)    area[i] += a[cur];
                cur++;
                temp >>= 1;
            }
        }
        memset(dp, -1, sizeof(dp));
        printf("Case %d: %s\n", kase++, S == x*y && dfs(ALL, min(x,y)) ? "Yes":"No");
    }
    
    return 0;
}