solves binary substing

Author: anishLearnsToCode

README.md

@@ -1,8 +1,8 @@
 # LeetCode Algorithms
 
-![problems-solved](https://img.shields.io/badge/Problems%20Solved-167/2081-1f425f.svg)
-![problems-solved-java](https://img.shields.io/badge/Java-167/2081-1abc9c.svg)
-![problems-solved-python](https://img.shields.io/badge/Python-167/2081-1abc9c.svg)
+![problems-solved](https://img.shields.io/badge/Problems%20Solved-168/2081-1f425f.svg)
+![problems-solved-java](https://img.shields.io/badge/Java-168/2081-1abc9c.svg)
+![problems-solved-python](https://img.shields.io/badge/Python-168/2081-1abc9c.svg)
 [![PRs Welcome](https://img.shields.io/badge/PRs-welcome-brightgreen.svg)](CONTRIBUTING.md)
 [![cp](https://img.shields.io/badge/also%20see-Competitve%20Programming-1f72ff.svg)](https://github.com/anishLearnsToCode/competitive-programming)
 
@@ -188,7 +188,7 @@
 | 687 | [Longest Univalue Path](https://leetcode.com/problems/longest-univalue-path) | |
 | 690 | [Employee Importance](https://leetcode.com/problems/employee-importance) | |
 | 693 | [Binary Number with Alternating Bits](https://leetcode.com/problems/binary-number-with-alternating-bits) | [![Java](assets/java.png)](src/BinaryNumberWithAlternatingBits.java) [![Python](assets/python.png)](python/binary_number_with_alternating_bits.py) |
-| 696 | [Count Binary Substrings](https://leetcode.com/problems/count-binary-substrings) | |
+| 696 | [Count Binary Substrings](https://leetcode.com/problems/count-binary-substrings) | [![Java](assets/java.png)](src/CountBinarySubstrings.java) [![Python](assets/python.png)](python/count_binary_substrings.py) |
 | 697 | [Degree of an Array](https://leetcode.com/problems/degree-of-an-array) | |
 | 700 | [Search in a Binary Search Tree](https://leetcode.com/problems/search-in-a-binary-search-tree) | |
 | 703 | [Kth Largest Element in a Stream](https://leetcode.com/problems/kth-largest-element-in-a-stream) | |

python/count_binary_substrings.py

@@ -0,0 +1,11 @@
+class Solution:
+    def countBinarySubstrings(self, s: str) -> int:
+        binarySubstrings, previous, current = 0, 0, 1
+        index = 1
+        while index < len(s):
+            if s[index - 1] != s[index]:
+                binarySubstrings += min(previous, current)
+                previous, current = current, 1
+            else: current += 1
+            index += 1
+        return binarySubstrings + min(previous, current)

src/CountBinarySubstrings.java

@@ -0,0 +1,13 @@
+public class CountBinarySubstrings {
+    public int countBinarySubstrings(String string) {
+        int binarySubStrings = 0, prev = 0, current = 1;
+        for (int index = 1 ; index < string.length() ; index++) {
+            if (string.charAt(index - 1) != string.charAt(index)) {
+                binarySubStrings += Math.min(prev, current);
+                prev = current;
+                current = 1;
+            } else current++;
+        }
+        return binarySubStrings + Math.min(prev, current);
+    }
+}