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Split the array and add the first part to the end

There is a given array and split it from a specified position, and move the first splitted part of the array and then add to the end of array
 



Examples: 

Input : arr[] = {12, 10, 5, 6, 52, 36}
            k = 2
Output : arr[] = {5, 6, 52, 36, 12, 10}
Explanation : here k is two so first two elements are splitted and they are added at the end of array

Input : arr[] = {3, 1, 2}
           k = 1
Output : arr[] = {1, 2, 3}
Explanation :here k is one  so first one  element  are splitted and it  is added at the end of array

Simple Solution: We will rotate the elements of the array one by one.



Implementation:





























Output
5 6 52 36 12 10 

Time complexity: O(n*k). 
Space complexity: O(1), since no extra space has been taken.

Another approach: Another approach is to make a temporary array with double the size and copy our array element into a new array twice and then copy the element from the new array to our array by taking the rotation as starting index up to the length of our array.

Below is the implementation of the above approach.












# Python3 program to split array and
# move first part to end.
 
# Function to split array and
# move first part to end
def SplitAndAdd(A, length, rotation):
 
    # make a temporary array with double
    # the size and each index is initialized to 0
    tmp = [ 0 for i in range(length * 2)]
 
    # copy array element in to new array twice
    for i in range(length):
        tmp[i] = A[i]
        tmp[i + length] = A[i]
 
    for i in range(rotation,
                   rotation + length, 1):
        A[i - rotation] = tmp[i];
      
# Driver code
arr = [12, 10, 5, 6, 52, 36]
n = len(arr)
position = 2
SplitAndAdd(arr, n, position);
for i in range(n):
    print(arr[i], end = " ")
print()
 
# This code is contributed by SOUMYA SEN




// C# program to split array
// and move first part to end.
using System;
 
class GFG
{
 
    // Function to split array and
    // move first part to end
    public static void SplitAndAdd(int[] A,
                                   int length,
                                   int rotation)
    {
 
        // make a temporary array with double the size
        int[] tmp = new int[length * 2];
 
        // copy array element in to new array twice
        Array.Copy(A, 0, tmp, 0, length);
        Array.Copy(A, 0, tmp, length, length);
        for (int i = rotation; i < rotation + length; i++)
        {
            A[i - rotation] = tmp[i];
        }
    }
 
    // Driver code
    public static void Main(string[] args)
    {
        int[] arr = new int[] {12, 10, 5, 6, 52, 36};
        int n = arr.Length;
        int position = 2;
 
        SplitAndAdd(arr, n, position);
 
        for (int i = 0; i < n; ++i)
        {
            Console.Write(arr[i] + " ");
        }
    }
}
 
// This code is contributed by kumar65




<script>
// Javascript program to split
// array and move first
// part to end.
     
    // Function to split array and
    // move first part to end
    function SplitAndAdd(A,Length,rotation)
    {
        // make a temporary array
        // with double the size
        let tmp = new Array(Length*2);
        for(let i=0;i<tmp.length;i++)
        {
            tmp[i]=0;
        }
          
        // copy array element in to new array twice
         
        for(let i=0;i<Length;i++)
        {
            tmp[i] = A[i]
            tmp[i + Length] = A[i]
        }
         
        for(let i=rotation;i<rotation+Length;i++)
        {
            A[i - rotation] = tmp[i];
        }
         
    }
     
    // Driver code
    let arr=[12, 10, 5, 6, 52, 36];
    let n = arr.length;
    let position = 2;
    SplitAndAdd(arr, n, position);
     
    for (let i = 0; i < n; ++i)
        document.write(arr[i] + " ");
     
     
    // This code is contributed by avanitrachhadiya2155
     
</script>

Output
5 6 52 36 12 10 

Time complexity: O(n)
Space complexity: O(2*n)

An efficient O(n) solution is discussed in the following post: Split the array and add the first part to the end | Set 2
This problem is noted but array rotation problem and we can apply the optimized O(n) array rotation methods here. 
Program for array rotation 
Block swap algorithm for array rotation
Reversal algorithm for array rotation 
Quickly find multiple left rotations of an array | Set 1 
Print left rotation of array in O(n) time and O(1) space

 


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