#include<stdio.h>
#include<algorithm>
using namespace std;
int pile[22];//initial array size
int pile_cmp(const void*a,const void *b)
{
    return *(int*)a-*(int*)b;
}
int main()
{
     int num;
     scanf("%d",&num);
     int sum=0;
     for(int i=0;i<num;i++){
         scanf("%d",&(pile[i]));
         sum+=pile[i];
     }
         if(sum==0)printf("0\n");
         else{
         qsort(pile,num,sizeof(int),pile_cmp);
             int ptr=num-1,min=2000000,min_p,tmp;
         while( ptr>=0 && sum ){
         while(ptr>=0 && (sum-(pile[ptr]<<1))<0)ptr--;
         if(ptr<0)ptr++;
         tmp=pile[ptr]<<1;
         if(abs(sum-tmp)<min){
             sum=abs(sum-tmp);
             min=sum;
         }
         ptr--;
        }
        printf("%d\n",min);
    }
     return 0;
}
before i submit this ,i submit another one ,which got AC but produce different answer with this one;however this one also got AC
I wasn't quite clear about what is the correct algorithm for this problem

Edited by author 02.08.2011 00:58

Edited by author 02.08.2011 01:05