Nov 5, 2018 · Oct 14, 2018 · Oct 14, 2018 · Nov 5, 2018 · Oct 16, 2018
diff --git a/GenerateParentheses.js b/GenerateParentheses.js
 /*
 https://leetcode.com/problems/generate-parentheses

 Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

 For example, given n = 3, a solution set is:

 [
  "((()))",
  "(()())",
  "(())()",
  "()(())",
  "()()()"
 ]
 */

 // ************************************************  Approach1  ************************************************
 var generateParenthesesApproach1 = function(n) {
  if(n === 0) { return [] };

  var str = "(".repeat(n);
    sol = [];

  genParAux(str, 0, 0, sol)
  return sol;
 };

 /*
 @param {string} str contains the string generated.
 @param {number} position Current position of the string where new parenthesis would be added.
 @param {string} leftParenthesis Amount for parenthesis left to be added.
 @param {[string]} sol array that contains the solution found so far.
 */

 var genParAux = function(str, position, leftParentheses, sol) {
  if(position === str.length) {
    var ret = str + ")".repeat(leftParentheses);
    sol.push(ret);
    return;
  }

  genParAux(str, position + 1, leftParentheses + 1, sol); // Don't insert anything
  if(leftParentheses === 0) { return; }

  for(var i = 1; i <= leftParentheses; i++) {
    var parString = ")".repeat(i);
    var partSol = str.slice(0, position) + parString + str.slice(position); // Insert i parentheses in the position
    genParAux(partSol, position + i + 1, leftParentheses - i + 1, sol);
  }
 }

 // ************************************************  Approach2  ************************************************
 var generateParenthesesApproach2 = function(n) {
  if(n === 0) { return [] };

  var sol = [];
  genParAuxApproach2("", 0, 0, 0, n * 2, sol)
  return sol;
 }

 var genParAuxApproach2 = function(str, leftPar, rightPar, index, totalCharCount, sol) {
  if(index === totalCharCount) {
    if(rightPar === leftPar) {
      sol.push(str);
    }
    return;
  }

  var strLeft = insertAt(str, index, "(");
  genParAuxApproach2(strLeft, leftPar + 1, rightPar, index + 1, totalCharCount, sol);

  if(rightPar === leftPar) { return; }

  var strRight = insertAt(str, index, ")");
  genParAuxApproach2(strRight, leftPar, rightPar + 1, index + 1, totalCharCount, sol);
 }

 var insertAt = function(str, position, value) {
  return str.slice(0, position) + value + str.slice(position);
 }

 function main() {
  console.log("Approach 1");
  [0, 1, 2, 3].forEach(function(elem) {
    console.log(`${elem}: ${generateParenthesesApproach2(elem)}`);
  })

  console.log("-------------");

  console.log("Approach 2");
  [0, 1, 2, 3].forEach(function(elem) {
    console.log(`${elem}: ${generateParenthesesApproach2(elem)}`);
  })
 }
 main();
 module.exports.main = main
diff --git a/Main.js b/Main.js
 var permutationWithoutDuplicates = require("./PermutationsWithoutDuplicates.js");
 var permutationWithDuplicates = require("./PermutationsWithDuplicates.js");
 var subsets = require("./Subsets.js");
 var generateParentheses = require("./GenerateParentheses.js")
 var maximunSubarray = require("./MaximunSubarray.js");
 var coinChange = require("./CoinChange.js");
 var nQueens = require("./NQueens.js");
 // permutationWithoutDuplicates.main();
 // permutationWithDuplicates.main();
 // subsets.main();
 // generateParentheses.main();
 // maximunSubarray.main();
 // coinChange.main();
 // nQueens.main();
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2,6 +2,7 @@
		var permutationWithoutDuplicates = require("./PermutationsWithoutDuplicates.js");
		var permutationWithDuplicates = require("./PermutationsWithDuplicates.js");
		var subsets = require("./Subsets.js");
		var generateParentheses = require("./GenerateParentheses.js")
		var maximunSubarray = require("./MaximunSubarray.js");
		var coinChange = require("./CoinChange.js");
		var nQueens = require("./NQueens.js");
Expand All		@@ -13,6 +14,7 @@ var floodFill = require("./FloodFill.js")
		// permutationWithoutDuplicates.main();
		// permutationWithDuplicates.main();
		// subsets.main();
		// generateParentheses.main();
		// maximunSubarray.main();
		// coinChange.main();
		// nQueens.main();
Expand Down