Added TreeNode util class

Author: ignacio-chiazzo

LeetcodeProblems/Add_Two_Numbers.js

@@ -44,34 +44,37 @@ var addTwoNumbers = function(l1, l2) {
 
   const head = number;
   while(l1 !== null || l2 !== null) {
-    var l1elem = 0;
-    var l2elem = 0;
+    var elem = carry;
     if(l1 !== null) {
-      l1elem = l1.val;
+      elem += l1.val;
       l1 = l1.next;
     }
     if(l2 !== null) {
-      l2elem = l2.val;
+      elem += l2.val;
       l2 = l2.next;
     }
 
-    elem = l1elem + l2elem + carry;
     number.next = new ListNode((elem % 10));
     number = number.next;
     carry = (elem >= 10) ? 1 : 0;
   }
-  if(carry === 1) {
+  if(carry === 1)
     number.next = new ListNode(1);
-    number = number.next;
-  }
   return head;
 };
 
-
 var main = function() {
   const list1 = ListNode.linkenList([1,2,3,4]);
   const list2 = ListNode.linkenList([1,2,3,4]);
   console.log(addTwoNumbers(list1, list2));
+
+  const list3 = ListNode.linkenList([1]);
+  const list4 = ListNode.linkenList([1,2]);
+  console.log(addTwoNumbers(list3, list4));
+
+  const list5 = ListNode.linkenList([]);
+  const list6 = ListNode.linkenList([1,2]);
+  console.log(addTwoNumbers(list5, list6));
 }
 
-main();
+module.exports.main = main;

LeetcodeProblems/Binary_Gap.js

@@ -53,9 +53,8 @@ var binaryGap = function(N) {
         currentDist++;
         N >>= 1; 
       }
-      if(N !== 0 && currentDist > maxDist) { 
+      if(N !== 0 && currentDist > maxDist)
         maxDist = currentDist;
-      }    
     }
   }
   return maxDist;
@@ -65,6 +64,5 @@ var main = function() {
   console.log(binaryGap(22)); // 10110
   console.log(binaryGap(8)); // 1000
 }
-main();
 
 module.exports.main = main;

LeetcodeProblems/Coin_Change.js

@@ -2,7 +2,9 @@
 Coin Change
 https://leetcode.com/problems/coin-change/
 
-You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination of the coins, return -1.
+You are given coins of different denominations and a total amount of money amount. 
+Write a function to compute the fewest number of coins that you need to make up that amount. 
+If that amount of money cannot be made up by any combination of the coins, return -1.
 
 Example 1:
 
@@ -18,19 +20,16 @@ You may assume that you have an infinite number of each kind of coin.
 */
 
 // Solution 3 
-var coinChange3 = function(coins, amount) {
+var coinChange = function(coins, amount) {
   var memo = [];
-
-  for(var i = 0; i <= amount; i++) {
+  for(var i = 0; i <= amount; i++)
     memo[i] = Number.POSITIVE_INFINITY;
-  }
-  memo[0] = 0;
 
+  memo[0] = 0;
   for(var i = 0; i < coins.length; i++) {
     const coin = coins[i];
-    for(var j = coin; j < memo.length; j++) {
+    for(var j = coin; j < memo.length; j++)
       memo[j] = min2(memo[j], memo[j - coin] + 1);
-    }
   }
 
   return (memo[amount] == Number.POSITIVE_INFINITY) ? -1 : memo[amount];
@@ -40,7 +39,6 @@ var min2 = function(a, b) {
   return (a < b) ? a : b;
 }
 
-
 // Solution 2
 var buildMemoKey = function(position, amount) {
   return position + "-" + amount;
@@ -54,9 +52,9 @@ var coinChange2 = function(coins, amount) {
 
 var coinChangeAux2 = function(coins, amount, pos, memo) {
   var key = buildMemoKey(pos, amount);
-  if(memo[key]) {
+  if(memo[key])
     return memo[key];
-  }
+    
   if(amount < 0) {
     return Number.POSITIVE_INFINITY; 
   } else if(amount == 0) {
@@ -98,18 +96,19 @@ var coinChangeAux1 = function(coins, amount, pos) {
 }
 
 var min = function(a, b, c) {
-  if(a < b) { return (a < c) ? a : c };
+  if(a < b) 
+    return (a < c) ? a : c;
   return (b < c) ? b : c;
 }
 
 function main() {
   console.log("-------------");
-  console.log("Approach 3")
-  console.log(coinChange3([], 3));
-  console.log(coinChange3([2], 3));
-  console.log(coinChange3([1, 2, 5], 11));
-  console.log(coinChange3([3,7,405,436], 8839));
-  console.log(coinChange3([370,417,408,156,143,434,168,83,177,280,117], 9953));
+  console.log("Solution Optimal")
+  console.log(coinChange([], 3));
+  console.log(coinChange([2], 3));
+  console.log(coinChange([1, 2, 5], 11));
+  console.log(coinChange([3, 7, 405, 436], 8839));
+  console.log(coinChange([370, 417, 408, 156, 143, 434, 168, 83, 177, 280, 117], 9953));
 }
 
 module.exports.main = main;

LeetcodeProblems/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js

@@ -27,27 +27,29 @@ Return the following binary tree:
  *     this.left = this.right = null;
  * }
  */
+
+var TreeNode = require('../utilsClasses/TreeNode').TreeNode;
+
 /**
  * @param {number[]} preorder
  * @param {number[]} inorder
  * @return {TreeNode}
  */
 var buildTree = function(preorder, inorder) {
   if(preorder === null || inorder === null || preorder.length !== inorder.length)
-      return nil;
+    return nil;
 
   return buildTreeAux(preorder, 0, preorder.length - 1, inorder, 0, inorder.length - 1);
 };
 
 var buildTreeAux = function(preorder, pl, ph, inorder, il, ih) {
   if(pl > ph || il > ih)
-      return null;
+    return null;
 
   const rootValue = preorder[pl];
   var countElementsLeft = 0;
-  while(inorder[il + countElementsLeft] !== rootValue) {
+  while(inorder[il + countElementsLeft] !== rootValue)
     countElementsLeft++;
-  }
 
   var ret = new TreeNode(rootValue);
   ret.left = buildTreeAux(preorder, pl + 1, pl + countElementsLeft, inorder, il, il + countElementsLeft - 1);
@@ -56,11 +58,6 @@ var buildTreeAux = function(preorder, pl, ph, inorder, il, ih) {
   return ret;
 }
 
-var TreeNode = function(val) {
-  this.val = val;
-  this.left = this.right = null;
-}
-
 var main = function() {
   console.log(buildTree([3,9,20,15,7], [9,3,15,20,7]));
 }

LeetcodeProblems/Deletion_Distance.js

@@ -19,7 +19,6 @@ input:  str1 = "", str2 = ""
 output: 0
 */
 
-
 // Solution 3 Using DP
 var deletionDistanceDP = function(str1, str2) {
   if(str1.length === 0)
@@ -54,9 +53,8 @@ var deletionDistance2 = function(str1, str2) {
 
 var deletionDistanceAux2 = function(str1, str2, pos1, pos2, memo) {
   const valueCashed = getValue(pos1, pos2, memo);
-  if(valueCashed !== undefined) {
+  if(valueCashed !== undefined)
     return valueCashed;
-  }
   var result;
 
   if(str1.length === pos1)
@@ -125,6 +123,4 @@ function main() {
   console.log(deletionDistanceDP("", "")); // =  0
 }
 
-main();
-
 module.exports.main = main

LeetcodeProblems/Design_Circular_Deque.js

@@ -15,7 +15,6 @@ getFront(): Gets the front item from the Deque. If the deque is empty, return -1
 getRear(): Gets the last item from Deque. If the deque is empty, return -1.
 isEmpty(): Checks whether Deque is empty or not. 
 isFull(): Checks whether Deque is full or not.
- 
 
 Example:
 
@@ -29,7 +28,6 @@ circularDeque.isFull();				// return true
 circularDeque.deleteLast();			// return true
 circularDeque.insertFront(4);			// return true
 circularDeque.getFront();			// return 4
- 
 
 Note:
 

LeetcodeProblems/Edit_Distance.js

@@ -27,45 +27,43 @@ inention -> enention (replace 'i' with 'e')
 enention -> exention (replace 'n' with 'x')
 exention -> exection (replace 'n' with 'c')
 exection -> execution (insert 'u')
-
 */
 
 // Optimal solution
 var minDistance = function(word1, word2) {
   var matrix = [];
   for(var i = 0; i <= word1.length; i++) {
-      matrix[i] = [];
-      for(var j = 0; j <= word2.length; j++) {
-          if(i === 0) {
-              matrix[i][j] = j;
-          } else if(j === 0){
-              matrix[i][j] = i;
-          } else {
-              matrix[i][j] = 0;
-          }
-      }
+    matrix[i] = [];
+    for(var j = 0; j <= word2.length; j++) {
+      if(i === 0)
+        matrix[i][j] = j;
+      else if(j === 0)
+        matrix[i][j] = i;
+      else
+        matrix[i][j] = 0;
+    }
   };
 
   for(var i = 1; i <= word1.length; i++) {
-      for(var j = 1; j <= word2.length; j++) {
-          if(word1.charAt(i - 1) === word2.charAt(j - 1)) {
-              matrix[i][j] = matrix[i - 1][j - 1];
-          } else {
-              matrix[i][j] = 1 + min(
-                  matrix[i - 1][j - 1],
-                  matrix[i - 1][j], // add
-                  matrix[i][j - 1]  // remove
-              );   
-          }
+    for(var j = 1; j <= word2.length; j++) {
+      if(word1.charAt(i - 1) === word2.charAt(j - 1)) {
+        matrix[i][j] = matrix[i - 1][j - 1];
+      } else {
+        matrix[i][j] = 1 + min(
+          matrix[i - 1][j - 1],
+          matrix[i - 1][j], // add
+          matrix[i][j - 1]  // remove
+        );   
       }
+    }
   }
 
   return matrix[word1.length][word2.length];
 };
 
 var min = function(a, b, c) {
   if(a < b) {
-      return (a < c) ? a : c;
+    return (a < c) ? a : c;
   }
   return (b < c) ? b : c;
 }
@@ -76,29 +74,26 @@ var minDistance2 = function(word1, word2) {
 }
 
 var minDistanceAux = function(word1, word2, iter1, iter2) {
- if(word1.length === iter1) {
-     return word2.length - iter2;
- }
+  if(word1.length === iter1)
+    return word2.length - iter2;
 
- if(word2.length === iter2) {
-     return word1.length - iter1;
- }
+  if(word2.length === iter2)
+    return word1.length - iter1;
 
- if(word1.charAt(iter1) === word2.charAt(iter2)) {
-     return minDistanceAux(word1, word2, iter1 + 1, iter2 + 1);
- }
-  
- return 1 + min(
-     minDistanceAux(word1, word2, iter1 + 1, iter2 + 1),
-     minDistanceAux(word1, word2, iter1, iter2 + 1), // add
-     minDistanceAux(word1, word2, iter1 + 1, iter2 ) // delete
- )
+  if(word1.charAt(iter1) === word2.charAt(iter2))
+    return minDistanceAux(word1, word2, iter1 + 1, iter2 + 1);
+ 
+  return 1 + min(
+    minDistanceAux(word1, word2, iter1 + 1, iter2 + 1),
+    minDistanceAux(word1, word2, iter1, iter2 + 1), // add
+    minDistanceAux(word1, word2, iter1 + 1, iter2 ) // delete
+  )
 };
 
 var min = function(a, b, c) {
-  if(a < b) {
-      return (a < c) ? a : c;
-  }
+  if(a < b)
+    return (a < c) ? a : c;
+  
   return (b < c) ? b : c;
 }
 
@@ -107,12 +102,11 @@ var main = function() {
   console.log("Approach 1");
   console.log(minDistance("ros", "horse"));
   console.log(minDistance("intention", "execution"));
+
   console.log("-------------");
   console.log("Approach 2");
   console.log(minDistance2("ros", "horse"));
   console.log(minDistance2("intention", "execution"));
 }
 
-main();
-
 module.exports.main = main;

LeetcodeProblems/Escape_The_Ghosts.js

@@ -43,16 +43,14 @@ The number of ghosts will not exceed 100.
  * @return {boolean}
  */
 var escapeGhosts = function(ghosts, target) {
-  var minDistanceGhost = Number.POSITIVE_INFINITY;
+  var distancePacman = getDistance([0,0], target);
   for(ghost in ghosts) {
-    const distance = getDistance(ghosts[ghost], target);
-    if(distance < minDistanceGhost) {
-      minDistanceGhost = distance;
-    }
+    const distanceGhost = getDistance(ghosts[ghost], target);
+    if(distancePacman > distanceGhost)
+      return false
   }
-  
-  var distancePacman = getDistance([0,0], target);
-  return distancePacman < minDistanceGhost;
+    
+  return true;
 };
 
 var getDistance = function(a, b) {
@@ -67,4 +65,4 @@ var main = function() {
   console.log(escapeGhosts([[2, 0]], [1, 0]));
 }
 
-module.exports.main = main
+module.exports.main = main