Create minimum-add-to-make-parentheses-valid.py

Author: kamyu104

Python/minimum-add-to-make-parentheses-valid.py

@@ -0,0 +1,16 @@
+# Time:  O(n)
+# Space: O(1)
+
+class Solution(object):
+    def minAddToMakeValid(self, S):
+        """
+        :type S: str
+        :rtype: int
+        """
+        add, bal, = 0, 0
+        for c in S:
+            bal += 1 if c == '(' else -1
+            if bal == -1:
+                add += 1
+                bal += 1
+        return add + bal