POJ 1157 LITTLE SHOP OF FLOWERS

//dp问题，不算太难

//写好之后一直不过，原因就是在第一列的初始化时，没有处理好。。。

 

#include < iostream >
using   namespace  std;

int  main()
{
     int   a[ 110 ][ 110 ],i,j,k,sum,max =- 10000 ,s[ 110 ][ 110 ];
     int  n,temp;
     while (scanf( " %d " , & n) != EOF)
    {
        memset(s, 0 , sizeof (s[ 0 ][ 0 ]));
         for (i = 0 ;i < n; ++ i)
             for (j = 1 ;j <= n; ++ j)
            {
                scanf( " %d " , & a[i][j - 1 ]);
                s[i][j] = s[i][j - 1 ] + a[i][j - 1 ];
            }
         for (i = 0 ;i < n; ++ i)
             for (j = i;j < n; ++ j)
            {
                sum = 0 ;
                 for (k = 0 ;k < n; ++ k)
                {
                    temp = s[k][j] - s[k][i];
                    sum += temp;
                     if (sum < 0 ) sum = 0 ;
                     else   if (sum > max)
                        max = sum;
                }
            }
        printf( " %d\n " ,max);
    }
     return   1 ;
}