solves #2609: FindTheLongestBalancedSubstringOfABinaryString in java

Author: anishLearnsToCode

README.md

@@ -811,8 +811,7 @@
 | 2595 | [Number of Even and Odd Bits](https://leetcode.com/problems/number-of-even-and-odd-bits)                                                                               |                                                                                   [![Java](assets/java.png)](src/NumberOfEvenAndOddBits.java)                                                                                    |                                                                                                                                   |
 | 2600 | [K Items With the Maximum Sum](https://leetcode.com/problems/k-items-with-the-maximum-sum)                                                                             |                                                                                   [![Java](assets/java.png)](src/KItemsWithTheMaximumSum.java)                                                                                   |                                                                                                                                   |
 | 2605 | [Form Smallest Number From Two Digit Arrays](https://leetcode.com/problems/form-smallest-number-from-two-digit-arrays)                                                 |                                                                            [![Java](assets/java.png)](src/FormSmallestNumberFromTwoDigitArrays.java)                                                                             |                                                                                                                                   |
-| 2605 | [Form Smallest Number From Two Digit Arrays](https://leetcode.com/problems/form-smallest-number-from-two-digit-arrays)                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |
-| 2609 | [Find the Longest Balanced Substring of a Binary String](https://leetcode.com/problems/find-the-longest-balanced-substring-of-a-binary-string)                         |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2609 | [Find the Longest Balanced Substring of a Binary String](https://leetcode.com/problems/find-the-longest-balanced-substring-of-a-binary-string)                         |                                                                       [![Java](assets/java.png)](src/FindTheLongestBalancedSubstringOfABinaryString.java)                                                                        |                                                                                                                                   |
 | 2614 | [Prime In Diagonal](https://leetcode.com/problems/prime-in-diagonal)                                                                                                   |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2639 | [Find the Width of Columns of a Grid](https://leetcode.com/problems/find-the-width-of-columns-of-a-grid)                                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2643 | [Row With Maximum Ones](https://leetcode.com/problems/row-with-maximum-ones)                                                                                           |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/FindTheLongestBalancedSubstringOfABinaryString.java

@@ -0,0 +1,26 @@
+// https://leetcode.com/problems/find-the-longest-balanced-substring-of-a-binary-string
+// T: O(n)
+// S: O(1)
+
+public class FindTheLongestBalancedSubstringOfABinaryString {
+    public int findTheLongestBalancedSubstring(String s) {
+        int result = 0;
+        for (int maxZeros = 0, maxOnes = 0, i = 0 ; i < s.length() ; i++) {
+            if (s.charAt(i) == '0') {
+                if (i - 1 >= 0 && s.charAt(i - 1) == '1') {
+                    result = Math.max(result, 2 * Math.min(maxOnes, maxZeros));
+                    maxOnes = 0;
+                    maxZeros = 1;
+                } else {
+                    maxZeros++;
+                }
+            } else {
+                maxOnes++;
+                if (i == s.length() - 1) {
+                    result = Math.max(result, 2 * Math.min(maxOnes, maxZeros));
+                }
+            }
+        }
+        return result;
+    }
+}