Write a modularized C++ program that will recursively generate all thepermutatio

ID: 3671030 • Letter: W

Question

Write a modularized C++ program that will recursively generate all thepermutations of any given n distinct objects (in this case use characters). For thisproject, use n = 6 as the maximum value for n, but your program should have the ability to work for any value of n with minimal code modification. (Note: this program will require a recursive routine that has a loop in it.)

Prompt the user interactively for the character data. Inputs should have space between the characters. Place the output in a file and inform the user the name of the file before exiting. Hereis an example of the input and the output file:

Enter the number of characters you want to permute => 3

Enter 3 characters => 1 2 3

Permutation 1: 1 2 3

Permutation 2: 1 3 2

Permutation 3: 2 1 3

Permutation 4: 2 3 1

Permutation 5: 3 2 1

Permutation 6: 3 1 2

** Add comments if you can will be helpful, Thanks

Explanation / Answer

// Program to print all combination of size r in an array of size n

#include <stdio.h>

void combinationUtil(int arr[],int data[],int start,int end, int index,int r);

// The main function that prints all combinations of size r

// in arr[] of size n. This function mainly uses combinationUtil()

void printCombination(int arr[],int n,int r)

{

// A temporary array to store all combination one by one

int data[r];

// Print all combination using temprary array 'data[]'

combinationUtil(arr, data, 0, n-1, 0, r);

}

/* arr[] ---> Input Array

data[] ---> Temporary array to store current combination

start & end ---> Staring and Ending indexes in arr[]

index ---> Current index in data[]

r ---> Size of a combination to be printed */

void combinationUtil(int arr[],int data[],int start,int end, int index,int r)

{

// Current combination is ready to be printed, print it

if (index == r)

{

for (int j=0; j<r; j++)

cout>> data[j];

cout>>" ";

return;

}

// replace index with all possible elements. The condition

// "end-i+1 >= r-index" makes sure that including one element

// at index will make a combination with remaining elements

// at remaining positions

for (int i=start; i<=end && end-i+1 >= r-index; i++)

{

data[index] = arr[i];

combinationUtil(arr, data, i+1, end, index+1, r);

}

// Driver program to test above functions

int main()

{

int arr[] = {1, 2, 3, 4, 5};

int r = 3;

int n =sizeof(arr)/sizeof(arr[0]);

printCombination(arr, n, r);

}

Output: