UVA 11181 Probability|Given

#include <cstring>
#include <cstdio>
#define N 25

int n,r;
bool vis[N];
double p[N],z,ans[N];
void dfs(int pos,int num)
{
    if(num==r)
    {
        double tmp=1;
        for(int i=1;i<=n;++i)
        {
            if(vis[i]) tmp*=p[i];
            else tmp*=(1-p[i]);
        }
        z+=tmp;
        for(int i=1;i<=n;++i) if(vis[i]) ans[i]+=tmp;
    }
    for(int i=pos+1;i<=n;++i)
    {
        vis[i]=1;
        dfs(i,num+1);
        vis[i]=0;
    }
}
int Main()
{
    int Case=0;
    while(scanf("%d%d",&n,&r)!=EOF)
    {
        if(n==0&&r==0) break;
        z=0;
        memset(ans,0,sizeof(ans));
        memset(vis,0,sizeof(vis));
        for(int i=1;i<=n;++i) scanf("%lf",&p[i]);
        dfs(0,0);
        printf("Case %d:\n",++Case);
        for(int i=1;i<=n;++i) printf("%.6lf\n",ans[i]/z);
    }
    return 0;
}
int sb=Main();
int main(int argc,char *argv[]){;}