leetcode 解题思路

Given two arraysarr1andarr2, the elements ofarr2are distinct, and all elements inarr2are also inarr1. Sort the elements ofarr1such that the relative ordering of items inarr1are the same as inarr2. Elements that don't appear inarr2should be...

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 defi

You're given strings J representing the types of stones that are jewels, and S representing the stones you have.  Each character in S is a type of stone you have.  You want to know how many of the sto...