Related Articles

# Deletions of “01” or “10” in binary string to make it free from “01” or “10”

• Difficulty Level : Easy
• Last Updated : 31 May, 2021

Given a binary string str, the task is to find the count of deletion of the sub-string “01” or “10” from the string so that the given string is free from these sub-strings. Print the minimum number of deletions.
Examples:

Input: str = “11010”
Output:
The resultant string will be “1”
Input: str = “1000101”
Output:
Resultant string, str = “0”

Approach: We are deleting “01” and “10” and the binary string contains only characters ‘0’ and ‘1’. Therefore, minimum number of deletions will be equal to the minimum of the count of ‘0’ and ‘1’.
Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach``#include ``using` `namespace` `std;` `// Function to return the count of deletions``// of sub-strings "01" or "10"``int` `substrDeletion(string str, ``int` `len)``{` `    ``// To store the count of 0s and 1s``    ``int` `count0 = 0, count1 = 0;` `    ``for` `(``int` `i = 0; i < len; i++) {``        ``if` `(str[i] == ``'0'``)``            ``count0++;``        ``else``            ``count1++;``    ``}` `    ``return` `min(count0, count1);``}` `// Driver code``int` `main()``{``    ``string str = ``"010"``;``    ``int` `len = str.length();``    ``cout << substrDeletion(str, len);` `    ``return` `0;``}`

## Java

 `// Java implementation of the approach``class` `GFG``{``    ` `// Function to return the count of deletions``// of sub-strings "01" or "10"``static` `int` `substrDeletion(String str, ``int` `len)``{` `    ``// To store the count of 0s and 1s``    ``int` `count0 = ``0``, count1 = ``0``;` `    ``for` `(``int` `i = ``0``; i < len; i++)``    ``{``        ``if` `(str.charAt(i) == ``'0'``)``            ``count0++;``        ``else``            ``count1++;``    ``}` `    ``return` `Math.min(count0, count1);``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``String str = ``"010"``;``    ``int` `len = str.length();``    ``System.out.println(substrDeletion(str, len));``}``}` `// This code is contributed by Code_Mech.`

## Python3

 `# Python3 implementation of the approach` `# Function to return the count of``# deletions of sub-strings "01" or "10"``def` `substrDeletion(string, length) :` `    ``# To store the count of 0s and 1s``    ``count0 ``=` `0``;``    ``count1 ``=` `0``;` `    ``for` `i ``in` `range``(length) :``        ``if` `(string[i] ``=``=` `'0'``) :``            ``count0 ``+``=` `1``;``        ``else` `:``            ``count1 ``+``=` `1``;` `    ``return` `min``(count0, count1);` `# Driver code``if` `__name__ ``=``=` `"__main__"` `:` `    ``string ``=` `"010"``;``    ``length ``=` `len``(string);``    ` `    ``print``(substrDeletion(string, length));` `# This code is contributed by Ryuga`

## C#

 `// C# implementation of the approach``using` `System;` `class` `GFG``{``    ` `// Function to return the count of deletions``// of sub-strings "01" or "10"``static` `int` `substrDeletion(``string` `str, ``int` `len)``{` `    ``// To store the count of 0s and 1s``    ``int` `count0 = 0, count1 = 0;` `    ``for` `(``int` `i = 0; i < len; i++)``    ``{``        ``if` `(str[i] == ``'0'``)``            ``count0++;``        ``else``            ``count1++;``    ``}` `    ``return` `Math.Min(count0, count1);``}` `// Driver code``public` `static` `void` `Main()``{``    ``string` `str = ``"010"``;``    ``int` `len = str.Length;``    ``Console.Write(substrDeletion(str, len));``}``}` `// This code is contributed by Ita_c.`

## Javascript

 ``
Output:
`1`

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.

My Personal Notes arrow_drop_up