HDU 1028 递推，如果用递归的话会超时

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>

int a[125][125];

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