C Exercises: Rotate an array by N positions

C Array: Exercise-39 with Solution

Write a program in C to rotate an array by N positions.
N.B.: The size of first array is (m+n) but only first m locations are populated remaining are empty. The second array is of size equal to n.

Pictorial Presentation:

Sample Solution:

C Code:

#include <stdio.h>
void shiftArr1Pos(int *arr1, int arrSize) 
{
    int i, temp;
      temp = arr1[0];
    for(i = 0; i < arrSize-1; i++) 
	{
        arr1[i] = arr1[i+1];
    }
    arr1[i] = temp;
}
void arr1Rotate(int *arr1, int arrSize, int rotFrom)
{
    int i;
    for(i = 0; i < rotFrom; i++)
	{
        shiftArr1Pos(arr1, arrSize);
    }
    return;
}
int main()
{
    int arr1[] = {0,3,6,9,12,14,18,20,22,25,27}; 
	int ctr = sizeof(arr1)/sizeof(arr1[0]);
    int i;
//---------- print original array ------------------------	
	printf("The given array is :  ");
	for(i = 0; i < ctr; i++)
	{
	printf("%d  ", arr1[i]);
    } 
    printf("\n");
//---------- print the values from 4th position ------------------------		
	printf("From 4th position the values of the array are :  ");
	for(i = 4; i < ctr; i++)
	{
	printf("%d  ", arr1[i]);
    } 
    printf("\n"); 
//---------- print the values before 4th position ------------------------	    
	printf("Before 4th position the values of the array are :  ");
	for(i = 0; i < 4; i++)
	{
	printf("%d  ", arr1[i]);
    } 
    printf("\n");     
//------------ after rotating the array --------------------  
    arr1Rotate(arr1, ctr, 4);
     printf("\nAfter rotating from 4th position the array is: \n");
    for(i = 0; i<ctr; i++)
	{
        printf("%d ", arr1[i]);
    }
    return 0;
}

Sample Output:

The given array is :  0  3  6  9  12  14  18  20  22  25  27  
From 4th position the values of the array are :  12  14  18  20  22  25  27  
Before 4th position the values of the array are :  0  3  6  9  

After rotating from 4th position the array is: 
12 14 18 20 22 25 27 0 3 6 9 

Flowchart:

C Programming Code Editor:

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