Create Solution2.java

Author: Jerring

solution/0032.Longest Valid Parentheses/Solution2.java

@@ -0,0 +1,32 @@
+class Solution {
+    public int longestValidParentheses(String s) {
+        int res = 0;
+        for (int i = 0, left = 0, right = 0; i < s.length(); ++i) {
+            if (s.charAt(i) == '(') {
+                ++left;
+            } else {
+                ++right;
+            }
+            if (left == right) {
+                res = Math.max(res, left << 1);
+            } else if (left < right) {
+                left = 0;
+                right = 0;
+            }
+        }
+        for (int i = s.length() - 1, left = 0, right = 0; i >= 0; --i) {
+            if (s.charAt(i) == '(') {
+                ++left;
+            } else {
+                ++right;
+            }
+            if (left == right) {
+                res = Math.max(res, left << 1);
+            } else if (left > right) {
+                left = 0;
+                right = 0;
+            }
+        }
+        return res;
+    }
+}