Algorithm

题目：28. Implement strStr() # Implement strStr().

题目：257. Binary Tree Paths # Given a binary tree, return all root-to-leaf paths. For example, given the following binary tree: 1 / 2 3 5 All root-to-leaf paths are: [“1->2->5”, “1->3”]

题目： # Given a string s consists of upper/lower-case alphabets and empty space characters ’ ‘, return the length of last word in the string. If the last word does not exist, return 0. Note: A word is defined as a character sequence consists of non-space characters only. For example, Given s = “Hello World”, return 5.