Time: 1 ms (54.42%), Space: 38.5 MB (27.88%) - LeetHub

Author: sachin10101998

minimum-add-to-make-parentheses-valid/minimum-add-to-make-parentheses-valid.java

@@ -0,0 +1,15 @@
+class Solution {
+    public int minAddToMakeValid(String S) {
+        int ans = 0, bal = 0;
+        for (int i = 0; i < S.length(); ++i) {
+            bal += S.charAt(i) == '(' ? 1 : -1;
+            // It is guaranteed bal >= -1
+            if (bal == -1) {
+                ans++;
+                bal++;
+            }
+        }
+
+        return ans + bal;
+    }
+}