Lewisr

摘要： Valid Palindrome:Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example, "A man, a plan, a canal: Panama" is a palindrome. "race a car... 阅读全文

摘要： Add Binary:Given two binary strings, return their sum (also a binary string). For example, a = "11" b = "1" Return "100". 题意：本题意思很明了，给定2个String，分别存储了用二进制表示的数，实现二进制的加法。 思路：从右向左逐位相加，注意进位即可。 代码： public S... 阅读全文

摘要： Contains Duplicate II: Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the difference between i and ji... 阅读全文