To rotate the matrix elements using c

Question:

Write a c program to rotate the matrix elements for any length of matrix.

Logic:

• Get the array elements from the user.
• Then pick the second row first element.
• And swap all elements in boundary sequentially to make rotation.
• Then repeat the process for all other elements.
• When we goes to middle of the matrix shows no rotation is left.
• Al last we get rotated matrix.

Program:

#include<stdio.h>
void main()
{
	int a[20][20],r,c,i,j,cr,pr,m=0,n=0,x,y;
	clrscr();
	printf("enter the row size:");
	scanf("%d",&r);
	printf("enter the column size:");
	scanf("%d",&c);
	x=r;y=c;
	printf("enter the elements:");
	for(i=0;i<r;i++)
	{
		for(j=0;j<c;j++)
		{
			scanf("%d",&a[i][j]);
		}
	}
	printf("Before rotation:\n");
	for(i=0;i<x;i++)
	{
		for(j=0;j<y;j++)
		{
			printf("%d ",a[i][j]);
		}
		printf("\n");
	}
	while(r>m&&c>n)
	{
		if(m+1==r||n+1==c)//exits when no other rotation is available
		{
			break;
		}
		pr=a[m+1][n];//previous element to swap
		for(i=m;i<c;i++)//rotates the top row
		{
			cr=a[m][i];
			a[m][i]=pr;
			pr=cr;
		}
		for(i=m+1;i<r;i++)//rotates the right column
		{
			cr=a[i][c-1];
			a[i][c-1]=pr;
			pr=cr;
		}
		for(i=c-2;i>=m;i--)//rotates the bottom row
		{
			cr=a[r-1][i];
			a[r-1][i]=pr;
			pr=cr;
		}
		for(i=r-2;i>m;i--)//rotates the left column
		{
			cr=a[i][n];
			a[i][n]=pr;
			pr=cr;
		}
		r--;c--;//decrements row and column for another rotation
		m++;n++;
	}
	printf("After rotation:\n");
	for(i=0;i<x;i++)
	{
		for(j=0;j<y;j++)
		{
			printf("%d ",a[i][j]);
		}
		printf("\n");
	}
	getch();
}