Create minimum-insertions-to-balance-a-parentheses-string.py

Author: kamyu104

Python/minimum-insertions-to-balance-a-parentheses-string.py

@@ -0,0 +1,22 @@
+# Time:  O(n)
+# Space: O(1)
+
+class Solution(object):
+    def minInsertions(self, s):
+        """
+        :type s: str
+        :rtype: int
+        """
+        add, bal = 0, 0
+        for c in s:
+            if c == '(':
+                if bal > 0 and bal%2:
+                    add += 1
+                    bal -= 1
+                bal += 2
+            else:
+                bal -= 1
+                if bal < 0:
+                    add += 1
+                    bal += 2
+        return add + bal