摘要：
Given two strings s and t which consist of only lowercase letters. String t is generated by random shuffling string s and then add one more letter at 阅读全文
摘要：
Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: Note: You may assume the 阅读全文
摘要：
Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the rans 阅读全文
摘要：
Given a positive integer num, write a function which returns True if num is a perfect square else False. Note: Do not use any built-in library functio 阅读全文
摘要：
Given two arrays, write a function to compute their intersection. Example 1: Example 2: Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4] Output: [9,4] Exam 阅读全文