# Minimum number of digits to be removed so that no two consecutive digits are same

• Difficulty Level : Basic
• Last Updated : 07 Jul, 2022

Given a number N. The task is to count the minimum number of digits to be removed from the number so that no two consecutive digits are the same.
Examples

Input : N = 11344
Output : 2
Explanation : Remove the digit 1 from 2nd place and 4 from the end so that the number becomes 134. Thus no two consecutive digits are same. Hence answer is 2.
Input : N = 55553
Output : 3
Explanation : Remove the digit 5 from the 2nd, 3rd and 4th places so that the number becomes 53. Thus no two consecutive digits are same. Hence answer is 3.

The problem can be easily solved if we just count the number of consecutive pairs of equal digits. That would be the minimum number of digits to remove from the given number so that no two consecutive digits are the same.
Below is the implementation of the above approach:

## C++

 `// CPP program to count the minimum number``// of digits to be removed from a number so that``// no two consecutive digits are same` `#include ``using` `namespace` `std;` `// Function to count the minimum number of digits``// to remove from a number so that no two``// consecutive digits are same.``int` `countConsecutive(``int` `n)``{``    ``// convert the number to string``    ``string s = to_string(n);` `    ``// initialize counting variable``    ``int` `count = 0;` `    ``for` `(``int` `i = 0; i < s.size() - 1; i++)``        ``if` `(s[i] == s[i + 1]) ``// check if two consecutive digits are same``            ``count++;` `    ``return` `count;``}` `// Driver code``int` `main()``{``    ``int` `n = 44522255;``    ``cout << countConsecutive(n);``    ``return` `0;``}`

## Java

 `// Java program to count the minimum``// number of digits to be removed``// from a number so that no two``// consecutive digits are same``import` `java.lang.*;``import` `java.util.*;` `class` `GFG``{``    ` `// Function to count the minimum number``// of digits to remove from a number so``// that no two consecutive digits are same.``static` `int` `countConsecutive(``int` `n)``{``    ``// convert the number to string``    ``String s = Integer.toString(n);` `    ``// initialize counting variable``    ``int` `count = ``0``;` `    ``for` `(``int` `i = ``0``; i < s.length() - ``1``; i++)``        ` `        ``// check if two consecutive``        ``// digits are same``        ``if` `(s.charAt(i) == s.charAt(i + ``1``))``            ``count++;` `    ``return` `count;``}` `// Driver code``public` `static` `void` `main(String args[])``{``    ``int` `n = ``44522255``;``    ``System.out.println(countConsecutive(n));``}``}` `// This code is contributed``// by Akanksha Rai(Abby_akku)`

## Python 3

 `# Python 3 program to count the``# minimum number of digits to be``# removed from a number so that``# no two consecutive digits are same` `# Function to count the minimum``# number of digits to remove from``# a number so that no two consecutive``# digits are same.``def` `countConsecutive(n):` `    ``# convert the number to string``    ``s ``=` `str``(n)` `    ``# initialize counting variable``    ``count ``=` `0` `    ``for` `i ``in` `range``(``len``(s) ``-` `1``):``        ` `        ``# check if two consecutive``        ``# digits are same``        ``if` `(s[i] ``=``=` `s[i ``+` `1``]):``            ``count ``+``=` `1` `    ``return` `count` `# Driver code``if` `__name__ ``=``=` `"__main__"``:``    ``n ``=` `44522255``    ``print``( countConsecutive(n))` `# This code is contributed``# by ChitraNayal`

## C#

 `// C# program to count the minimum``// number of digits to be removed``// from a number so that no two``// consecutive digits are same``using` `System;` `class` `GFG``{``// Function to count the minimum number``// of digits to remove from a number so``// that no two consecutive digits are same.``static` `int` `countConsecutive(``int` `n)``{``    ``// convert the number to string``    ``string` `s = n.ToString();` `    ``// initialize counting variable``    ``int` `count = 0;` `    ``for` `(``int` `i = 0; i < s.Length - 1; i++)``        ` `        ``// check if two consecutive``        ``// digits are same``        ``if` `(s[i] == s[i + 1])``            ``count++;` `    ``return` `count;``}` `// Driver code``public` `static` `void` `Main()``{``    ``int` `n = 44522255;``    ``Console.Write(countConsecutive(n));``}``}` `// This code is contributed``// by Akanksha Rai(Abby_akku)`

## PHP

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## Javascript

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Output:

`4`

Time Complexity: O(n)
Auxiliary Space: O(logn)

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