Matrix Layer Rotation - HackerRank Coding Challenge | https://www.hackerrank.com/challenges/matrix-rotation

mat_rot.c

/*
You are given a 2D matrix, a, of dimension MxN and a positive integer R. You have to rotate the matrix R times and print the resultant matrix. Rotation should be in anti-clockwise direction.
Rotation of a 4x5 matrix is represented by the following figure. Note that in one rotation, you have to shift elements by one step only (refer sample tests for more clarity).

Matrix-rotation
It is guaranteed that the minimum of M and N will be even.
Input
First line contains three space separated integers, M, N and R, where M is the number of rows, N is number of columns in matrix, and R is the number of times the matrix has to be rotated. 
Then M lines follow, where each line contains N space separated positive integers. These M lines represent the matrix.

Output 
Print the rotated matrix.

Constraints 
2 <= M, N <= 300 
1 <= R <= 109 
min(M, N) % 2 == 0 
1 <= aij <= 108, where i ∈ [1..M] & j ∈ [1..N]

Sample Input #00

4 4 1
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
Sample Output #00

2 3 4 8
1 7 11 12
5 6 10 16
9 13 14 15
*/

//Code


#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>

int min(int a,int b)
{
   return (a<b)?a:b;
}

int main()
{
	int m,n,r,i,j,a[50][50],initial,num_rect=0,count=0,x,y,k,row,col;
	
	printf("Enter the number of rows and coloumns : ");
	scanf("%d%d",&m,&n);
	
	
	num_rect = (min(m,n))/2;
	
	printf("Enter the number of rotations\n");
	scanf("%d",&r);
	
	printf("Enter the matrix \n");
	
		for(i=1;i<=m;i++)
			for(j=1;j<=n;j++)
				scanf("%d",&a[i][j]);
	

		for(k=1;k<=r;k++)
		{	
			
			x=m;
			y=n;
			
			
			for(count=1;count<=num_rect;count++)
			{

				row=count;
				col=count;
				initial = a[count][count];
					
					do
					{							
					 		
						if( (col+1) <= y )
						{
							a[row][col] = a[row][col+1];		
							col++;
							
						}
						else if( (row+1) <= x )
						{
							a[row][col] = a[row+1][col];
							row++;  						 
						}	
						
					}while(!(row==x && col==y));
			
					do
					{	
					 
						if( (col-1) >= count )
						{
							a[row][col] = a[row][col-1];
							col--;
						}
						else if( (row-1) >= count )
						{
							a[row][col] = a[row-1][col];
							row--;
						}										
								
			
					}while(!(  (row-1)==count && col==count)  );
			
					a[row][col] = initial;
					x--;
					y--;
			 }
		}
	 
	 printf("\nMatrix rotated %d times is : \n",r);
	 for(i=1;i<=m;i++)
	 {
	 	for(j=1;j<=n;j++)
	 	{
	 		printf(" %d ",a[i][j]);
	 	}
	 	printf("\n");
	 }
	 return 0;
}