摘要： Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Exampl 阅读全文

摘要： 题目： Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. For example, two is written as II in Roman numeral, just two on 阅读全文

摘要： Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward. Example 1: Example 2: Example 3: 阅读全文

摘要： 题目： Given a 32-bit signed integer, reverse digits of an integer. Example 1: Example 2: Example 3: Note: Assume we are dealing with an environment whic 阅读全文

摘要： 题目： 输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字，例如，如果输入如下4 X 4矩阵： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 则依次打印出数字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10. 代码： 时间复杂度： 阅读全文

摘要： 题目： You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes co 阅读全文

摘要： 注意：写代码前首先要考虑鲁棒性。 复杂问题画图分析。 运行时间：27ms 时间复杂度：o(n) 阅读全文

摘要： Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function 阅读全文

摘要： 1、做树有关的题多数用递归 2、记得检查空指针异常 阅读全文

摘要： 输入两个单调递增的链表，输出两个链表合成后的链表，当然我们需要合成后的链表满足单调不减规则。 思路：刚开始没想到递归，用递归很方便。 阅读全文