https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/

Author: ignacio-chiazzo

LeetcodeProblems/Algorithms/Minimum_Add_To_Make_Parentheses_Valid.js

@@ -0,0 +1,69 @@
+/*
+Minimum Add to Make Parentheses Valid
+https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/
+
+A parentheses string is valid if and only if:
+
+It is the empty string,
+It can be written as AB (A concatenated with B), where A and B are valid strings, or
+It can be written as (A), where A is a valid string.
+You are given a parentheses string s. In one move, you can insert a parenthesis at any position of the string.
+
+For example, if s = "()))", you can insert an opening parenthesis to be "(()))" or a closing parenthesis to be "())))".
+Return the minimum number of moves required to make s valid.
+ 
+Example 1:
+
+Input: s = "())"
+Output: 1
+Example 2:
+
+Input: s = "((("
+Output: 3
+ 
+Constraints:
+
+1 <= s.length <= 1000
+s[i] is either '(' or ')'.
+*/
+
+
+var minAddToMakeValid = function(s) {
+  var opening = 0;
+  var extraParClosing = 0;
+  
+  for(let i = 0; i < s.length; i++) {
+      if(s.charAt(i) == "(") {
+          opening++;
+      } else if(s.charAt(i) == ")") {
+          if(opening == 0) {
+              extraParClosing++;
+          } else {
+              opening--;;
+          }
+      } 
+  }
+  return extraParClosing + opening;
+};
+
+// Solution 2 using a queue
+var minAddToMakeValidUsingQueue = function(s) {
+  var queue = [];
+  var extraParClosing = 0;
+  
+  for(let i = 0; i < s.length; i++) {
+      if(s.charAt(i) == "(") {
+          queue.push(s.charAt(i))
+      } else if(s.charAt(i) == ")") {
+          if(queue.length > 0) {
+              queue.pop();
+          } else {
+              extraParClosing++;
+          }
+      } 
+  }
+
+  return extraParClosing + queue.length;
+};
+
+module.exports.minAddToMakeValid = minAddToMakeValid;

LeetcodeProblemsTests/Algorithms/Minimum_Add_To_Make_Parentheses_Valid_Test.js

@@ -0,0 +1,13 @@
+const assert = require('assert');
+const minAddToMakeValid = require('../../LeetcodeProblems/Algorithms/Minimum_Add_To_Make_Parentheses_Valid').minAddToMakeValid;
+
+var test = function() {
+  assert.strictEqual(1, minAddToMakeValid("()("));
+  assert.strictEqual(3, minAddToMakeValid("((("));
+  assert.strictEqual(0, minAddToMakeValid("()"));
+  assert.strictEqual(1, minAddToMakeValid(")"));
+  assert.strictEqual(1, minAddToMakeValid("("));
+  assert.strictEqual(2, minAddToMakeValid(")("));
+};
+
+module.exports.test = test;

README.md

@@ -43,6 +43,7 @@ To run a specific problem in your console run  `node <problem_file_path>` (e.g.
 | [Max Area Of Island ](/LeetcodeProblems/Algorithms/Max_Area_Of_Island.js)                                       | Medium | https://leetcode.com/problems/max-area-of-island/ |
 | [Max Consecutive Ones III ](/LeetcodeProblems/Algorithms/Max_Consecutive_Ones_III.js)                           | Medium | https://leetcode.com/problems/max-consecutive-ones-iii |
 | [Maximal Square ](/LeetcodeProblems/Algorithms/Maximal_Square.js)                                               | Medium | https://leetcode.com/problems/maximal-square/ |
+| [Minimum Add to Make Parentheses Valid ](/LeetcodeProblems/Algorithms/Minimum_Add_To_Make_Parentheses_Valid.js) | Medium | https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/ |
 | [Minimum Size Subarray](/LeetcodeProblems/Algorithms/Minimum_Size_Subarray.js)                                  | Medium | https://leetcode.com/problems/minimum-size-subarray-sum |
 | [Permutations ](/LeetcodeProblems/Algorithms/Permutations.js)                                                   | Medium | https://leetcode.com/problems/permutations/ |
 | [Permutations II ](/LeetcodeProblems/Algorithms/Permutations_II.js)                                             | Medium | https://leetcode.com/problems/permutations-ii/ |