POJ1011-Sticks

http://poj.org/problem?id=1011

 

#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
int p[65],vis[65],s,j,n;
bool cmp(int a,int b)
{
    return a>b;
}
int dfs(int sum,int k,int cnt)
{  
    if(cnt==s) 
       return 1;
    else if(sum==j) 
       return dfs(0,0,cnt+1);
    else
    {
        int pre,i;
        for(pre=0,i=k;i<n;i++) 
           if(vis[i]&&p[i]!=pre&&p[i]+sum<=j)
           {
               pre=p[i];                                                                   
               vis[i]=0;
               if(dfs(sum+p[i],i+1,cnt)) 
                  break;                         
               vis[i]=1;                                                    
               if(k==0) 
                  return 0;                                               
           }
           if(i==n) 
              return 0; 
           else 
              return 1; 
    }
}
int main(void)
{
    int i,sum;
    while(cin>>n,n)
    {
        for(i=sum=0;i<n;i++)
        {
            cin>>p[i];
            sum+=p[i];
        }
        sort(p,p+n,cmp);                                                         
        for(j=p[0];j<sum;j++) 
           if(sum%j==0)
           {
               s=sum/j;
               memset(vis,1,sizeof(vis));
               if(dfs(0,0,0)) 
                  break;
           }
           if(j==sum) 
              cout<<sum<<endl; 
           else 
              cout<<j<<endl;
    }
    return 0;
}