C语言神奇的幻方

#include<stdio.h>

int main()
{
   int data[40][40]={0};
   int N;
   scanf("%d",&N);
   int k=1;
   int i,j,m,n;
   i = 0;
   j = N/2;
   data[i][j] = k;
   m=i,n=j; // k-1 的行和列
   k++;
   while(k<=N*N)
   {
        if(m==0&&n!=N-1){data[N-1][n+1] = k;m=N-1,n=n+1;}
        else if(m!=0&&n==N-1){data[m-1][0] = k;m=m-1,n=0;}
        else if(m==0&&n==N-1) {data[m+1][n] = k;m=m+1,n=n;}
        else if(m!=0&&n!=N-1&&data[m-1][n+1]==0){data[m-1][n+1]=k;m=m-1,n=n+1;}
        else{data[m+1][n] = k;m=m+1,n=n;}
        k++;
   }
   for(i=0;i<N;i++)
    {
        for(j=0;j<N;j++)
    {
       printf("%d ",data[i][j]);
    }
        printf("\n");
    }
   return 0;
}