Recursive program to reverse a number

Recursive program to reverse a number

Given a number , write a Recursive program to reverse a number .

Sample input:-

253

Sample output:-

Reverse of 253 is  352

Recursive program to reverse a number:-

The objective of this code is to reverse the number .

Method 1:-

In this method we will create a function ReverseNumber()  in which we will pass two parameter first for number and second for the Reverse number . In second parameter we will store the final and i.e reverse of the number . And the base case for this function is if n==0 the return second parameter.

C Code:-

#include<stdio.h>

// recursive function to reverse the number
int ReverseNumber(int n, int reverse)
{
    if(n==0)
      return reverse;
    else
    {
        int r=n%10;
        n=n/10;
        reverse=reverse*10+r;
        return ReverseNumber(n,reverse);
    }
}

// Driver function
int main()
{
    int n;
    printf("Enter a number\n");
    scanf("%d",&n);
    printf("Reverse of %d is %d ",n,ReverseNumber(n,0));
    return 0;
}

Output:-

Enter a number 
256 
Reverse of 256 is 652

 

Method 2:-

In this method instead of using the second parameter we will use a global variable Rev_num for storing the reverse of the number.

#include<stdio.h>

int Rev_num=0;
// recursive function to reverse the number
void ReverseNumber(int n)
{
    if(n)
    {
        int r=n%10;
        Rev_num=Rev_num*10+r;
        n=n/10;
        ReverseNumber(n);
    }
    
}

// Driver function
int main()
{
    int n;
    printf("Enter a number\n");
    scanf("%d",&n);
    ReverseNumber(n);
    printf("Reverse of %d is %d ",n,Rev_num);
    return 0;
}

Output:-

Enter a number 
256 
Reverse of 256 is 652

 

 

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