Remove repeated digits in a given number

Given an integer, remove consecutive repeated digits from it.

Examples:

Input: x = 12224
Output: 124

Input: x = 124422
Output: 1242

Input: x = 11332
Output: 132

We need to process all digits of n and remove consecutive representations. We can go through all digits by repeatedly dividing n with 10 and taking n%10.

C++

// C++ program to remove repeated digits 
#include <iostream> 
using namespace std; 
  
long int removeRecur(long int n) 
{ 
    // Store first digits as previous digit 
    int prev_digit = n % 10; 
  
    // Initialize power 
    long int pow = 10; 
    long int res = prev_digit; 
  
    // Iterate through all digits of n, note that 
    // the digits are processed from least significant 
    // digit to most significant digit. 
    while (n) { 
        // Store current digit 
        int curr_digit = n % 10; 
  
        if (curr_digit != prev_digit) { 
            // Add the current digit to the beginning 
            // of result 
            res += curr_digit * pow; 
  
            // Update previous result and power 
            prev_digit = curr_digit; 
            pow *= 10; 
        } 
  
        // Remove last digit from n 
        n = n / 10; 
    } 
  
    return res; 
} 
  
// Drive program 
int main() 
{ 
    long int n = 12224; 
    cout << removeRecur(n); 
    return 0; 
} 

Java

// Java program to remove repeated digits 
import java.io.*; 
  
class GFG { 
  
    static long removeRecur(long n) 
    { 
          
        // Store first digits as previous 
        // digit 
        long prev_digit = n % 10; 
      
        // Initialize power 
        long pow = 10; 
        long res = prev_digit; 
      
        // Iterate through all digits of n, 
        // note that the digits are  
        // processed from least significant 
        // digit to most significant digit. 
        while (n>0) { 
              
            // Store current digit 
            long curr_digit = n % 10; 
      
            if (curr_digit != prev_digit)  
            { 
                // Add the current digit to 
                // the beginning of result 
                res += curr_digit * pow; 
      
                // Update previous result 
                // and power 
                prev_digit = curr_digit; 
                pow *= 10; 
            } 
      
            // Remove last digit from n 
            n = n / 10; 
        } 
      
        return res; 
    } 
      
    // Drive program 
    public static void main (String[] args) 
    { 
        long n = 12224; 
          
        System.out.println(removeRecur(n)); 
    } 
} 
  
// This code is contributed by anuj_67. 

Python3

# Python 3 program to remove repeated digits 
  
def removeRecur(n): 
      
    # Store first digits as previous digit 
    prev_digit = n % 10
  
    # Initialize power 
    pow = 10
    res = prev_digit 
  
    # Iterate through all digits of n, note  
    # that the digits are processed from  
    # least significant digit to most  
    # significant digit. 
    while (n): 
          
        # Store current digit 
        curr_digit = n % 10
  
        if (curr_digit != prev_digit): 
              
            # Add the current digit to the  
            # beginning of result 
            res += curr_digit * pow
  
            # Update previous result and power 
            prev_digit = curr_digit 
            pow *= 10
  
        # Remove last digit from n 
        n = int(n / 10) 
      
    return res 
  
# Driver Code 
if __name__ == '__main__': 
    n = 12224
    print(removeRecur(n)) 
  
# This code is contributed by  
# Surendra_Gangwar 

C#

// C# program to remove repeated digits 
using System; 
  
class GFG { 
  
    static long removeRecur(long n) 
    { 
          
        // Store first digits as previous 
        // digit 
        long prev_digit = n % 10; 
      
        // Initialize power 
        long pow = 10; 
        long res = prev_digit; 
      
        // Iterate through all digits of n, 
        // note that the digits are  
        // processed from least significant 
        // digit to most significant digit. 
        while (n > 0) { 
              
            // Store current digit 
            long curr_digit = n % 10; 
      
            if (curr_digit != prev_digit)  
            { 
                // Add the current digit to 
                // the beginning of result 
                res += curr_digit * pow; 
      
                // Update previous result 
                // and power 
                prev_digit = curr_digit; 
                pow *= 10; 
            } 
      
            // Remove last digit from n 
            n = n / 10; 
        } 
      
        return res; 
    } 
      
    // Drive program 
    public static void Main () 
    { 
        long n = 12224; 
          
        Console.WriteLine(removeRecur(n)); 
    } 
} 
  
// This code is contributed by anuj_67. 

PHP

<?php 
// PHP program to remove  
// repeated digits 
  
function removeRecur($n) 
{ 
      
    // Store first digits  
    // as previous digit 
    $prev_digit = $n % 10; 
  
    // Initialize power 
    $pow = 10; 
    $res = $prev_digit; 
  
    // Iterate through all digits 
    // of n, note that the digits  
    // are processed from least 
    // significant digit to most  
    // significant digit. 
    while ($n) 
    { 
          
        // Store current digit 
        $curr_digit = $n%10; 
  
        if ($curr_digit != $prev_digit) 
        { 
            // Add the current digit 
            // to the beginning of  
            // result 
            $res += $curr_digit * $pow; 
      
            // Update previous result 
            // and power 
            $prev_digit = $curr_digit; 
            $pow *= 10; 
        } 
  
        // Remove last digit 
        // from n 
        $n = $n / 10; 
    } 
  
    return $res; 
} 
  
    // Driver Code 
    $n = 12224; 
    echo removeRecur($n); 
      
// This ocde is contributed by ajit. 
?> 

Output:

This article is contributed by Kartik. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above

My Personal Notes

C++

Java

Python3

C#

PHP

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