Print left rotation of array in O(n) time and O(1) space in C Program.


We are given an array of some size n and multiple integer values, we need to rotate an array from a given index k.

We want to rotate an array from a index k like −

Examples

Input: arr[] = {1, 2, 3, 4, 5}
   K1 = 1
   K2 = 3
   K3 = 6
Output:
   2 3 4 5 1
   4 5 1 2 3
   2 3 4 5 1

Algorithm

START
Step 1 -> Declare function void leftRotate(int arr[], int n, int k)
   Declare int cal = k% n
   Loop For int i=0 and i<n and i++
      Print arr[(cal+i)%n]
   End
Step 2 -> In main()
   Declare array a[]={ 1,2,3,4}
   Declare int size=sizeof(a)/sizeof(a[0])
   Declare int k=1
   Call leftRotate(a, size, k)
   Set k=2
   Call leftRotate(a, size, k)
   Set k=3
   leftRotate(a, size, k)
STOP

Example

#include <bits/stdc++.h>
using namespace std;
void leftRotate(int arr[], int n, int k){
   int cal = k % n;
   for (int i = 0; i < n; i++)
      cout << (arr[(cal + i) % n]) << " ";
   cout << "
"; } int main(){    int a[] = { 1,2,3,4};    int size = sizeof(a) / sizeof(a[0]);    int k = 1;    leftRotate(a, size, k);    k = 2;    leftRotate(a, size, k);    k = 3;    leftRotate(a, size, k);    return 0; }

Output

if we run above program then it will generate following output

2 3 4 1
3 4 1 2
4 1 2 3

Updated on: 22-Aug-2019

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