Longest valid parentheses solution

Author: joshguha

Diff for: 32_longest_valid_parentheses.py

@@ -0,0 +1,47 @@
+import pdb
+class Solution(object):
+    # def longestValidParentheses(self, s):
+    #     """
+    #     :type s: str
+    #     :rtype: int
+    #     """
+    #     ls = len(s)
+    #     start = [0] * (ls + 1)
+    #     all = [0] * (ls + 1)
+    #     for i in reversed(range(ls - 1)):
+    #         if s[i] == '(':
+    #             if s[i + 1] == ')':
+    #                 start[i] = 2
+    #             if start[i + 1] + i + 1 < ls and s[start[i + 1] + i + 1] == ')':
+    #                 start[i] = 2 + start[i + 1]
+    #             if start[start[i] + i] > 0:
+    #                 start[i] += start[start[i] + i]
+    #         all[i] = max(start[i], all[i + 1])
+    #     return all[0]
+
+    def longestValidParentheses(self, s):
+        # https://leetcode.com/discuss/87988/my-easy-o-n-java-solution-with-explanation
+        ls = len(s)
+        stack = []
+        data = [0] * ls
+        for i in range(ls):
+            curr = s[i]
+            if curr == '(':
+                stack.append(i)
+            else:
+                if len(stack) > 0:
+                    data[i] = 1
+                    data[stack.pop(-1)] = 1
+        tep, res = 0, 0
+        for t in data:
+            if t == 1:
+                tep += 1
+            else:
+                res = max(tep, res)
+                tep = 0
+        return max(tep, res)
+
+if __name__ == '__main__':
+    s = Solution()
+    # print s.longestValidParentheses(")(((((()())()()))()(()))(")
+    print s.longestValidParentheses(')()())')