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

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: 2
The resultant string will be “1”

Input: str = “1000101”
Output: 3
Resultant string, str = “0”

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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. `

Output:

```1
```

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.