題目： A message containing letters from A-Z is being encoded to numbers using the following mapping way: 'A' -> 1 'B' -> 2 ... 'Z' -> 26 Beyond that, now the encoded string can also contain the character ‘*’, whic

Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? 思考：快慢指針，快指針一次走兩步，慢指針一次一步。若快指針跟慢指針指向同一個結點，則有環。若快指針到達鏈表末尾即指向NULL

原題鏈接在這里：https://leetcode.com/problems/word-ladder/ leetcode70。題目： Given two words (beginWord?and?endWord), and a dictionary's word list, find the length of shortest transformation sequence from?beginWord?to?endWord, such that:

題目連接 https://leetcode.com/problems/course-schedule-ii/?? Course Schedule II Description There are a total of n courses you have to take, labeled from 0 to n - 1. leetcode 課程表？Some courses may have prerequisites, for example to take course 0 you ha

Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: A: a1 → a2 ↘ c1 → c2 → c3 ↗ B: b1 → b2 → b3 begin to intersect at node c1. /*** Definition for singly-linked

Intersection of Two Linked Lists: Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: A: a1 → a2↘c1 → c2 → c3↗ B: b1 → b2 → b3 leetcode121，begin to intersect at

? ? Implement Trie (Prefix Tree)208. Implement Trie (Prefix Tree)Add and Search Word - Data structure design211. Add and Search Word - Data structure designWord Search II?212. Word Search IIPalindrome Pairs? leetcode中文。轉載于:https://www.cnblogs.com/r

LeetCode——Maximum Depth of Binary Tree Question Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node. Answer /*** Definition for a binary tree node

題目如下： Python代碼： def isPalindrome(self, x):""":type x: int:rtype: bool"""if(x>=0):s = int(str(x)[::-1])if(x==s):return Trueelse:return Falseelse:return False leetcode 53？? 轉載于:https://www.c

Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of?every?node never differ by more than 1. 思考：求二叉樹高的變形，加上