Gold Balanced Lineup(hash)

http://poj.org/problem?id=3274

*****

 #include <stdio.h>
 #include <iostream>
 #include <string.h>
 #include <stdlib.h>
 using namespace std;
 const int N=;
 const int MOD=;
 int Maxdis,k;
 int c[N][],sum[N][];
 int vis[N][];

 struct node
 {
     int row_i;
     struct node *next;
 }*hash[N];
 bool cmp(int a1,int b1)
 {
     for (int i = ; i < k; i++)
     {
         if (c[a1][i]!=c[b1][i])
             return false;
     }
     return true;
 }
 void Hash(int row_i)
 {
     int key = ,i = ;
     while(i < k)
     {
         key = key*+c[row_i][i];
         i++;
     }
     key=abs(key)%MOD;
     if (!hash[key])
     {
         hash[key] = new node;
         hash[key]->row_i = row_i;
         hash[key]->next = NULL;
     }
     else
     {
         struct node *p = hash[key];
         if(cmp(p->row_i,row_i))
         {
             if (Maxdis < row_i-(p->row_i))
                 Maxdis = row_i-(p->row_i);
             return ;
         }
         while(p->next)
         {
             if (cmp(p->next->row_i,row_i))
             {
                 if (Maxdis < row_i-(p->next->row_i))
                     Maxdis = row_i-(p->next->row_i);
                 return ;
             }
             p = p->next;
         }
         p->next = new node;
         p->next->row_i = row_i;
         p->next->next = NULL;
     }
     return ;
 }
 int main()
 {
     int n;
     scanf("%d %d",&n,&k);
     for (int i = ; i < k; i++)
     {
         c[][i] = ;
         sum[][i] = ;
     }
     memset(hash,,sizeof(hash));
     Hash();
     Maxdis = ;
     for (int i = ; i <= n; i++)
     {
         int num;
         scanf("%d",&num);
         for (int j = ; j < k; j++)
         {
             vis[i][j]=num%;
             num/=;
             sum[i][j] = sum[i-][j]+vis[i][j];
             c[i][j] = sum[i][j]-sum[i][];
         }
         Hash(i);
     }
     printf("%d\n",Maxdis);
     return ;
 }