2609. Find the Longest Balanced Substring of a Binary String

Author: jony-ion

Diff for: jony-java/src/test/java/com/doublejony/leetcode/Leet2609.java

@@ -0,0 +1,82 @@
+package com.doublejony.leetcode;
+
+import com.google.common.base.Stopwatch;
+import com.tngtech.java.junit.dataprovider.DataProvider;
+import com.tngtech.java.junit.dataprovider.DataProviderRunner;
+import com.tngtech.java.junit.dataprovider.UseDataProvider;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static com.doublejony.common.AssertResolve.resolve;
+
+@RunWith(DataProviderRunner.class)
+public class Leet2609 {
+
+    @DataProvider
+    public static Object[][] testCase() {
+        // @formatter:off
+        return new Object[][]{
+                {
+                        "001",
+                        2
+                },
+                {
+                        "01000111",
+                        6
+                },
+                {
+                        "00111",
+                        4
+                },
+                {
+                        "111",
+                        0
+                },
+        };
+        // @formatter:on
+    }
+
+    @Test
+    @UseDataProvider("testCase")
+    public void solution(String s, int expected) {
+
+        Stopwatch timer = Stopwatch.createStarted();
+        resolve(Thread.currentThread().getStackTrace()[1].getMethodName(), expected,
+                new Solution().findTheLongestBalancedSubstring(s), timer.stop());
+    }
+
+    class Solution {
+
+        public int findTheLongestBalancedSubstring(String s) {
+            int zCount = 0;
+            int oCount = 0;
+            boolean isOne = false;
+
+            int answer = 0;
+            for (int i = 0; i < s.length(); i++) {
+                char c = s.charAt(i);
+                switch (c) {
+                    case '0':
+                        if (isOne) {
+                            zCount = 0;
+                            oCount = 0;
+                            isOne = false;
+                        }
+                        zCount++;
+                        break;
+                    case '1':
+                        oCount++;
+                        isOne = true;
+                        break;
+                }
+
+                if (zCount >= oCount) {
+                    answer = Math.max(answer, oCount * 2);
+                }
+            }
+
+            return answer;
+        }
+    }
+
+}