#include <bits/stdc++.h>
using namespace std;
/*Prototype for utility functions */
void printArray(int arr[], int size);
void swap(int arr[], int fi, int si, int d);
void leftRotate(int arr[], int d, int n)
{
/* Return If number of elements to be rotated
is zero or equal to array size */
if(d == 0 || d == n)
return;
/*If number of elements to be rotated
is exactly half of array size */
if(n - d == d)
{
swap(arr, 0, n - d, d);
return;
}
/* If A is shorter*/
if(d < n - d)
{
swap(arr, 0, n - d, d);
leftRotate(arr, d, n - d);
}
else /* If B is shorter*/
{
swap(arr, 0, d, n - d);
leftRotate(arr + n - d, 2 * d - n, d); /*This is tricky*/
}
}
/*UTILITY FUNCTIONS*/
/* function to print an array */
void printArray(int arr[], int size)
{
int i;
for(i = 0; i < size; i++)
cout << arr[i] << " ";
cout << endl;
}
/*This function swaps d elements starting at index fi
with d elements starting at index si */
void swap(int arr[], int fi, int si, int d)
{
int i, temp;
for(i = 0; i < d; i++)
{
temp = arr[fi + i];
arr[fi + i] = arr[si + i];
arr[si + i] = temp;
}
}
// Driver Code
int main()
{
int arr[] = {1, 2, 3, 4, 5, 6, 7};
leftRotate(arr, 2, 7);
printArray(arr, 7);
return 0;
}
// This code is contributed by Rath Bhupendra
I found this code on the geek for geeks website. The code is used to rotate the elements of an array. It is mentioned as block swap algorithm in the website, my questions are:
Can we add integers to an array in c++ as given in the else part of the left rotate function while passing the arguments (arr+n-d)?
How can we add integers to an array?
I tried adding an integer to an array in an online compiler and it didn't work. But the above code works perfectly giving the desired output 34567.
The link to the website is https://www.geeksforgeeks.org/block-swap-algorithm-for-array-rotation/.