https://leetcode.com/problems/construct-binary-tree-from-inorder-and-postorder-traversal/ Given inorder and postorder traversal of a tree, construct the binary tree. Note: You may assume that duplicates do not exist in the tree. Code # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution(object): …
Continue reading “Leetcode 106: Construct Binary Tree from Inorder and Postorder Traversal”
https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ Given preorder and inorder traversal of a tree, construct the binary tree. Note: You may assume that duplicates do not exist in the tree. Code # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution(object): def …
Continue reading “Leetcode 105: Construct Binary Tree from Preorder and Inorder Traversal”
https://leetcode.com/problems/best-time-to-buy-and-sell-stock-iii/ Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete at most two transactions. Note:You may not engage in multiple transactions at the same time (ie, you must sell the stock before you …
Continue reading “Leetcode 123: Best Time to Buy and Sell Stock III”
https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii/ Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy one and sell one share of the stock multiple times). However, you may not engage …
Continue reading “Leetcode 122: Best Time to Buy and Sell Stock II”
https://leetcode.com/problems/best-time-to-buy-and-sell-stock/ Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock), design an algorithm to find the maximum profit. Code import sys class …
Continue reading “Leetcode 121: Best Time to Buy and Sell Stock”
https://leetcode.com/problems/minimum-depth-of-binary-tree/ Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. Code # Definition for a binary tree node. # class TreeNode(object): # def __init__(self, x): # self.val = x # self.left = None …
Continue reading “Leetcode 111: Minimum Depth of Binary Tree”
https://leetcode.com/problems/largest-number/ Given a list of non negative integers, arrange them such that they form the largest number. For example, given [3, 30, 34, 5, 9], the largest formed number is 9534330. Note: The result may be very large, so you need to return a string instead of an integer. Code class Solution(object): def largestNumber(self, …
https://leetcode.com/problems/path-sum-ii/ Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ …
https://leetcode.com/problems/path-sum-ii/ Given a binary tree and a sum, find all root-to-leaf paths where each path’s sum equals the given sum. For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ / \ 7 2 5 1 return [ [5,4,11,2], [5,8,4,5] ] …
https://leetcode.com/problems/valid-anagram/ Given two strings s and t, write a function to determine if t is an anagram of s. For example,s = “anagram”, t = “nagaram”, return true.s = “rat”, t = “car”, return false. Note:You may assume the string contains only lowercase alphabets. Follow up:What if the inputs contain unicode characters? How would you …