IncredibleThings

摘要： Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum. Note: A leaf is a node with no children. Exampl 阅读全文

摘要： Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and 阅读全文

摘要： Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Example 1: Input: [1,3,null,null,2 阅读全文

摘要： Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2. Note: The length of both num1 and num2 is < 5100. Both num1 and num2 contains only digits 0-9. Bot 阅读全文

摘要： 用 PriorityQueue 阅读全文

摘要： Given a non-empty array of integers, return the third maximum number in this array. If it does not exist, return the maximum number. The time complexity must be in O(n). Example 1: Input: [3, 2, 1] Ou 阅读全文

摘要： Write a program that outputs the string representation of numbers from 1 to n, however: If the number is divisible by 3, output "fizz". If the number is divisible by 5, output "buzz". If the number ... 阅读全文

摘要： Write a program that outputs the string representation of numbers from 1 to n. But for multiples of three it should output “Fizz” instead of the number and for the multiples of five output “Buzz”. F... 阅读全文

摘要： Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters. This is case sensitive, for example "Aa" is not cons... 阅读全文

摘要： 思路：看到题目就知道要用DFS做，注意结束递归的条件 阅读全文