C++ Program to Print array after it is right rotated K times

Given an Array of size N and a values K, around which we need to right rotate the array. How to quickly print the right rotated array?
Examples :

Input: Array[] = {1, 3, 5, 7, 9}, K = 2.
Output: 7 9 1 3 5
Explanation:
After 1st rotation - {9, 1, 3, 5, 7}
After 2nd rotation - {7, 9, 1, 3, 5}

Input: Array[] = {1, 2, 3, 4, 5}, K = 4.
Output: 2 3 4 5 1      

Approach:

1. We will first take mod of K by N (K = K % N) because after every N rotations array will become the same as the initial array. 
   
2. Now, we will iterate the array from i = 0 to i = N-1 and check, 
   • If i < K, Print rightmost Kth element (a[N + i -K]). Otherwise, 
     
   • Print array after ‘K’ elements (a[i – K]). 
     

Below is the implementation of the above approach. 

C++

// C++ implementation of right rotation
// of an array K number of times
#include<bits/stdc++.h>
using namespace std;

// Function to rightRotate array
void RightRotate(int a[], int n, int k)
{

    // If rotation is greater
    // than size of array
    k = k % n;

    for(int i = 0; i < n; i++)
    {
       if(i < k)
       {

           // Printing rightmost
           // kth elements
           cout << a[n + i - k] << " ";
       }
       else
       {

           // Prints array after
           // 'k' elements
           cout << (a[i - k]) << " ";
       }
    }
    cout << "
";
}

// Driver code
int main()
{
    int Array[] = { 1, 2, 3, 4, 5 };
    int N = sizeof(Array) / sizeof(Array[0]);
    int K = 2;

    RightRotate(Array, N, K);
}

// This code is contributed by Surendra_Gangwar

Output:

4 5 1 2 3

Time complexity : O(n) 
Auxiliary Space : O(1)

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