Create 1249. Minimum Remove to Make Valid Parentheses (#449)

Author: Chayandas07

1249. Minimum Remove to Make Valid Parentheses

@@ -0,0 +1,44 @@
+class Solution {
+public:
+    string minRemoveToMakeValid(string s) {
+        int open = 0, close = 0;
+        string ans;
+        //traverse from start to end to eleminate extra closing braces
+        for (const char& c : s) {
+            if (c != '(' && c != ')') {
+                ans += c;
+            } else if (c == '(') {
+                open++;
+                ans += c;
+            } else if (open > 0) {
+                ans += c;
+                open--;
+            }
+        }
+
+       //traverse from end to start to remove extra opening braces
+        if (open > 0) {
+             int n = ans.length();
+            s = ans;
+            ans = "";
+            open = 0, close = 0;
+            for (int i = n - 1; i >= 0; i--) {
+                char c = s[i];
+                if (c != '(' && c != ')') {
+                    ans += c;
+                } else if (c == ')') {
+                    close++;
+                    ans += c;
+                } else if (close > 0) {
+                    ans += c;
+                    close--;
+                }
+            }
+        }
+        else{
+            return ans;
+        }
+        reverse(ans.begin(), ans.end());
+        return ans;
+    }
+};