Spiral Pattern

Write a program to print the numbers in following pattern. 

1 2 3 

8 9 4 

7 6 5 

Input and Output Constraints: 

Input consists of an integer n which denotes the number of rows and columns. Input must be not more than 25. 

Output must consists of numbers from 1 to n*n printed in spiral pattern. 

Sample Input: 

3 

Pattern is: 

1 2 3 

8 9 4 

7 6 5 

Sample Input: 

4 

Pattern is:  

1 2 3 4 

12 13 14 5 

11 16 15 6 

10 9 8 7 

Program Code:

#include <stdio.h>

//#define SIZE 4 // Size is always even

int main()

{

int i, j, N,SIZE;

scanf("%d",&SIZE);

int board[SIZE][SIZE];

int left, top;

left = 0;

top  = SIZE - 1;

N   = 1;

for(i=1; i<=SIZE; i++, left++, top--)

{

// Fill from left to right

for(j=left; j<=top; j++, N++)

{

 board[left][j] = N;

}

 // Fill from top to down

for(j=left+1; j<=top; j++, N++)

{

board[j][top] = N;

}

 // Fill from right to left

for(j=top-1; j>=left; j--, N++)

{

board[top][j] = N;

}

// Fill from down to top

for(j=top-1; j>=left+1; j--, N++)

{

board[j][left] = N;

}

}

// Print the pattern

printf("PATTERN IS:\n");

for(i=0; i<SIZE; i++)

{

for(j=0; j<SIZE; j++)

{

printf("%d ", board[i][j]);

}

printf("\n");

}

return 0;

}