Array Rotation in C
Array rotation
In this Article we’ll be learning about program for array rotation of elements of array – left and right to a specified number of times. An array is said to be right rotated if all the selected elements were moved towards right by one position.
Array Rotation In C
Method Discussed :
- Method 1 : Using Temporary array.
- Method 2 : Rotate one by one.
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.
Method 1 : Code in C
Run
//Write a program for array rotation in C
#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 = 3;
int temp[k];
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 < n; i++)
printf("%d ", arr[i]);
return 0;
}Output
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Method 2 :
In this method, we will rotate the elements one by one by shifting them.
Method 2 : Code in C
Run
//Write a program for array rotation in C
#include<stdio.h>
void leftRotatebyOne(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 leftRotate(int arr[], int k, int n)
{
for (int i = 0; i < k; i++)
leftRotatebyOne(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]);
leftRotate(arr, 3, n);
for (int i = 0; i < n; i++)
printf("%d ", arr[i]);
return 0;
}Output
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