Question

Write a recursive C++ function that writes the digits of a positive decimal integer in reverse order.

Answer 1

Answer:

// here is code in c++.

#include <bits/stdc++.h>

using namespace std;

// recursive function to print digit of number in revers order

void rev_dig(int num)

{

  if(num==0)

  return;

  else

   {

       cout<<num%10<<" ";

       // recursive call

       rev_dig(num/10);

   }

}

// driver  function

int main()

{

   int num;

   cout<<"enter a number:";

   // read the number from user

   cin>>num;

   cout<<"digits in revers order: ";

   // call the function with number parameter

   rev_dig(num);

   

return 0;

}

Explanation:

Read the input from user and assign it to variable "num". Call the function "rev_dig" with "num" parameter.In this function it will find the last digit as  num%10 and print it. Then call the function itself with "num/10". This will print the second last digit. Similarly it will print all the digits in revers order.

Output:

enter a number:1234                                                                                                        

digits in revers order: 4 3 2 1

Diagram :