Programming
Aptitude
Syllabus
Interview Preparation
Interview Exp.
Off Campus
Program to Cyclically Rotate an Array by k Positions
Cyclically Rotate an Array by K
Here, in this page we will discuss the program for cyclically rotate an array by k positions. We are given with an integer array and value of k, and need to print the array after cyclically rotate it by k positions.
Method Discussed :
- Method 1 : Using Temporary Array.
- Method 2 : By rotating elements one by one.
- Method 3 : By Using the reversing Concept.
- Method 3 : Using juggling algorithm
Let’s discuss all the above methods one by one in brief,
Method 1 :
In this method we will declare an extra array to store some k elements. Here, k refers to number of rotations.
- Declare a temporary array of size k.
- Store the first k elements in temp[] array.
- Now, shift the remaining elements.
- After, shifting the elements add the elements of temp[] in the array
Code in C
Run
//Write a program to cyclically rotate an array by k
#include <stdio.h>
/* Driver program to test above functions */
int main()
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70};
int n = sizeof(arr)/sizeof(arr[0]);
int k = 4;
int temp_arr[k];
for(int i=0; i<k; i++)
temp_arr[i] = arr[i];
int x = k;
for(int i=0; x < n; i++){
arr[i] = arr[x++];
}
x = 0;
for(int i=n-k; i<n; i++)
arr[i] = temp_arr[x++];
for (int i = 0; i < n; i++)
printf("%d ", arr[i]);
return 0;
}
Code in C++
Run
//Write a program to cyclically rotate an array by k
#include <bits/stdc++.h>
using namespace std;
/* Driver program to test above functions */
int main()
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70};
int n = sizeof(arr)/sizeof(arr[0]);
int k = 4;
int temp_arr[k];
for(int i=0; i<k; i++)
temp_arr[i] = arr[i];
int x = k;
for(int i=0; x < n; i++){
arr[i] = arr[x++];
}
x = 0;
for(int i=n-k; i<n; i++)
arr[i] = temp_arr[x++];
for (int i = 0; i < n; i++)
cout<< arr[i]<<" ";
return 0;
}
Code in Java
Run
class Main {
public static void main(String[] args)
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70};
int n = arr.length;
int k = 4;
int[] temp;
temp = new int[n];
for(int i=0; i< k; i++)
temp[i] = arr[i];
int x = k;
for(int i=0; x < n; i++){
arr[i] = arr[x++];
}
x = 0;
for(int i=n-k; i<n; i++)
arr[i] = temp[x++];
for (int i = 0; i < 7; i++)
System.out.print(arr[i] + " ");
}
}
Output
50 60 70 10 20 30 40
Method 2 :
In this method we cyclically rotate the array by shifting elements one by one.
Code in C
Run
//Write a program to cyclically rotate an array by k
#include <stdio.h>
void cyclicRotatebyOne(int arr[], int n)
{
int temp = arr[0], i;
for (i = 0; i < n - 1; i++)
arr[i] = arr[i + 1];
arr[n-1] = temp;
}
void cyclicRotate(int arr[], int k, int n)
{
for (int i = 0; i < k; i++)
cyclicRotatebyOne(arr, n);
}
/* Driver program to test above functions */
int main()
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70};
int n = sizeof(arr)/sizeof(arr[0]);
int k = 4;
cyclicRotate(arr, k, n);
for (int i = 0; i < n; i++)
printf("%d ", arr[i]);
return 0;
}
Code in C++
Run
//Write a program to cyclically rotate an array by k
#include <bits/stdc++.h>
using namespace std;
void cyclicRotatebyOne(int arr[], int n)
{
int temp = arr[0], i;
for (i = 0; i < n - 1; i++)
arr[i] = arr[i + 1];
arr[n-1] = temp;
}
void cyclicRotate(int arr[], int k, int n)
{
for (int i = 0; i < k; i++)
cyclicRotatebyOne(arr, n);
}
/* Driver program to test above functions */
int main()
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70};
int n = sizeof(arr)/sizeof(arr[0]);
int k = 4;
cyclicRotate(arr, k, n);
for (int i = 0; i < n; i++)
cout<< arr[i]<<" ";
return 0;
}
Code in Python
Run
#Write a program for array rotation in Python
# Python3 program to rotate an array by
def leftRotate(arr, d, n):
for i in range(d):
leftRotatebyOne(arr, n)
# Function to left Rotate arr[] of size n by 1*/
def leftRotatebyOne(arr, n):
temp = arr[0]
for i in range(n-1):
arr[i] = arr[i + 1]
arr[n-1] = temp
# utility function to print an array */
def printArray(arr, size):
for i in range(size):
print ("% d"% arr[i], end =" ")
# Driver program to test above functions */
arr = [10, 20, 30, 40, 50, 60, 70]
leftRotate(arr, 4, 7)
printArray(arr, 7)
Code in Java
Run
class Main {
public static void main(String[] args)
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70};
int n = arr.length;
int k = 4;
int[] temp;
temp = new int[n];
for(int i=0; i<k; i++)
temp[i] = arr[i];
int x = k;
for(int i=0; x < n; i++){
arr[i] = arr[x++];
}
x = 0;
for(int i=n-k; i<n; i++)
arr[i] = temp[x++];
for (int i = 0; i < 7; i++)
System.out.print(arr[i] + " ");
}
}
Output
50 60 70 10 20 30 40
Method 3 :
- Set K to points that element which comes at first position, i.e. K = N-K.
- Reverse the array from 0 to K-1 position.
- Again reverse the array from K to N-1 position.
- And then finally reverse the entire array.
- Doing so we will get the desired circularly rotated array by K position.
Code in C++
Run
//Write a program to cyclically rotate an array by k
#include <bits/stdc++.h>
using namespace std;
/* Driver program to test above functions */
int main()
{
std::vectorarr= { 10, 20, 30, 40, 50, 60, 70};
int n = arr.size();
int k = 3;
k = n-k;
reverse(arr.begin(), arr.begin()+k);
reverse(arr.begin()+k, arr.end());
reverse(arr.begin(), arr.end());
for (int i = 0; i < n; i++)
cout<< arr[i]<<" ";
return 0;
}
Output
50 60 70 10 20 30 40
Method 4 :
In this method we will use the concept of juggling algorithm for cyclically rotate the array by K positions.
You can check out the page for understanding it’s algorithm.
Code in C
Run
//Write a program to cyclically rotate an array by k
#include <stdio.h>
int gcd(int a, int b) {
if (b == 0)
return a;
else
return gcd(b, a % b);
}
void ArrayRotate(int A[], int n, int k) {
int d = -1, i, temp, j;
for (i = 0; i < gcd(n, k); i++) {
j = i;
temp = A[i];
while (1) {
d = (j + k) % n;
if (d == i) break;
A[j] = A[d];
j = d;
}
A[j] = temp;
}
}
void displayArray(int A[], int n) {
int i;
for (i = 0; i < n; i++)
printf("%d ", A[i]);
}
int main() {
int n = 7, i, k = 4;
int A[7] = {10, 20, 30, 40, 50, 60, 70};
ArrayRotate(A, n, k);
displayArray(A, n);
return 0;
}
Code in C++
Run
//Write a program to cyclically rotate an array by k
#include <bits/stdc++.h>
using namespace std;
int gcd(int a, int b) {
if (b == 0)
return a;
else
return gcd(b, a % b);
}
void ArrayRotate(int A[], int n, int k) {
int d = -1, i, temp, j;
for (i = 0; i < gcd(n, k); i++) {
j = i;
temp = A[i];
while (1) {
d = (j + k) % n;
if (d == i) break;
A[j] = A[d];
j = d;
}
A[j] = temp;
}
}
void displayArray(int A[], int n) {
int i;
for (i = 0; i < n; i++)
cout<<A[i]<<" ";
}
int main() {
int n = 7, i, k = 4;
int A[n] = {10, 20, 30, 40, 50, 60, 70};
ArrayRotate(A, n, k);
displayArray(A, n);
return 0;
}
Code in Java
Run
//Write a program to cyclically rotate an array by k
public class Main
{
public static int hcf(int a, int c)
{
if (c == 0)
return a;
else
return hcf(c, a % c);
}
//Function to left rotate array of by d number of rotations
public static void leftRotate(int arr[], int d, int n)
{
int i, l, m, temp;
for (i = 0; i < hcf(d, n); i++) // hcf(d,n) times the loop will iterate { // move i-th values of blocks temp = arr[i]; l = i; while (true) { m = l + d; if (m >= n) // The element has to be shifted to its rotated position
m = m - n;
if (m == i) // The element is already in its rotated position
break;
arr[l] = arr[m];
l = m;
}
arr[l] = temp;
}
}
// Main function
public static void main(String[] args)
{
int arr[] = { 10, 20, 30, 40, 50, 60, 70 };
int no_of_rotation = 4;
int n = arr.length;
leftRotate(arr, no_of_rotation, n);
for(int i = 0 ; i < n ; i++)
{
System.out.print(arr[i] + " ");
}
}
}
Code in Python
Run
import math
def leftRotate(arr, d, n):
for i in range(math.gcd(d, n)):
temp = arr[i]
j = i
while 1:
k = j + d
if k >= n:
k = k - n
if k == i:
break
arr[j] = arr[k]
j = k
arr[j] = temp
arr =[10, 20, 30, 40, 50, 60, 70]
n = len(arr)
no_of_rotations = 4
leftRotate(arr, no_of_rotations, n )
print(*arr)
Output
50 60 70 10 20 30 40
Prime Course Trailer
Related Banners
Get PrepInsta Prime & get Access to all 200+ courses offered by PrepInsta in One Subscription
Get over 200+ course One Subscription
Courses like AI/ML, Cloud Computing, Ethical Hacking, C, C++, Java, Python, DSA (All Languages), Competitive Coding (All Languages), TCS, Infosys, Wipro, Amazon, DBMS, SQL and others
Login/Signup to comment