Array Rotations Questions in C, Arrays: Left Rotation Hacker Rank Solution in C, Circular Array Rotation Hacker Rank Solution in C

Link to Question:
https://www.hackerrank.com/challenges/array-left-rotation/problem
https://www.hackerrank.com/challenges/ctci-array-left-rotation/problem

Program:
#include <stdio.h>

main()

{

 int n,i,d;

 scanf("%d%d",&n,&d);

 int a[n];

 for(i=0;i<n;i++)

  scanf("%d",&a[i]);

  for(i=d;i<d+n;i++)

   printf("%d ",a[i%n]); // we start printing from last index

 }

==============================================================
Circular Array Rotation

Link to Question
https://www.hackerrank.com/challenges/circular-array-rotation/problem

Program

#include <stdio.h>

int main()

{

    int n,i,k,q,j=0;

    scanf("%d%d%d",&n,&k,&q);

    int a[n],b[n];

    for(i=0;i<n;i++)

      scanf("%d",&a[i]);

    //after every n rotations, the rotated array becomes original array

    int r=k%n;

    for(int i=0;i<n;i++)

        b[(i+r)%n]=a[i];

    while(q--)

    {

        int id;

        scanf("%d",&id);

        printf("%d\n",b[id]);

    }

}

You can write the above program without using array b
by using
printf("%d\n",a[(n-(k%n)+m)%n]);

===============================================================================

Just understand the below two programs, you will be able to solve any array rotation problem
output:
5
1 2 3 4 5
2 3 4 5 1
3 4 5 1 2
4 5 1 2 3
5 1 2 3 4
1 2 3 4 5


#include <stdio.h>
main()
{
int n,i,j;
scanf("%d",&n);
int a[n];
for(i=0;i<n;i++)
scanf("%d",&a[i]);
for(i=1;i<n+1;i++)
{
for(j=i;j<i+n;j++)
printf("%d ",a[j%n]); // we start printing from first index
printf("\n");
}
}

=======================================================================
output:
5
1 2 3 4 5
5 1 2 3 4
4 5 1 2 3
3 4 5 1 2
2 3 4 5 1
1 2 3 4 5

#include <stdio.h>
main()
{
int n,i,j;
scanf("%d",&n);
int a[n];
for(i=0;i<n;i++)
scanf("%d",&a[i]);
for(i=n-1;i>=0;i--)
{
for(j=i;j<i+n;j++)
printf("%d ",a[j%n]); // we start printing from last index
printf("\n");
}
}