Zmeika

//https://otvet.mail.ru/question/211343438
//populate array with values 1,2..., quite exotic order
//print the following:
// 0  0  0  0  0  0  0  0  0
// 1  0  0  0  0  0  0  0 26
// 2  8  0  0  0  0  0 21 27
// 3  9 13  0  0  0 18 22 28
// 4 10 14 16  0 17 19 23 29
// 5 11 15  0  0  0 20 24 30
// 6 12  0  0  0  0  0 25 31
// 7  0  0  0  0  0  0  0 32
// 0  0  0  0  0  0  0  0  0


#include <stdio.h>

#define NINE 9

int main()
{
   int i,j,counter,gap,top=0;
   int arr3[NINE][NINE]={0};
   counter = gap = 1;

   for(j=0;j<NINE;j++)
   {

       for(i=gap;i<NINE-gap;i++)
       {
           arr3[i][j]=counter++;
       }



        if(top||gap==5)//gap decreases from now on
        gap--,top++;
        else if(gap<5)//gap increases here
        gap++;


   }
   for(i=0;i<NINE;i++)
   {
       for(j=0;j<NINE;j++)
        printf("%4d",arr3[i][j]);
       printf("\n");
   }

    return 0;
}