Luck Competition

luck competition

思路：就是推公式，一开始受输入影响把输入的n一直按4算，wa了一发。

k=(sum+x)/n;x=n*k-sum;

m=k*2/3=n*k-sum;

k=3*sum/(3*n-2);

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
   int t,n,m,i,sum,cnt[110];
   scanf("%d",&t);
   while(t--)
   {
       scanf("%d",&n);
       memset(cnt,0,sizeof(cnt));
       sum=0;
       for(i=1;i<=n-1;i++)
       {
           scanf("%d",&m);
           cnt[m]++;
           sum+=m;
       }
       //cout<<sum<<endl;
       int M;
       double k,mm;
       k=3*sum*1.0/(3*n-2);
       //cout<<k<<endl;
       mm=2*sum*1.0/(3*n-2);
       //cout<<mm<<endl;
       M=mm;
       //cout<<M<<endl;
       //cout<<cnt[M]<<endl;
       printf("%d ",M);
       double ans;
       if(cnt[M]==0)
       {
           printf("1.00\n");
       }
       else
       {
           ans=1.0/(cnt[M]+1);
           cout<<fixed<<setprecision(2)<<ans<<endl;
       }
   }
}
//人一我百，人百我万
//时间