chengguotao的专栏

题目：Given an input string, reverse the string word by word.For example,Given s = "the sky is blue",return "blue is sky the".注意：通过从后向前遍历，遇到空格，就将后面的所有字符复制到StringBUffer中，并用一个int变量记录此次空格的

题目：A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.Return a deep copy of the list.思路：如图所示，直

题目：Given a 2D board containing 'X' and 'O', capture all regions surrounded by 'X'.A region is captured by flipping all 'O's into 'X's in that surrounded region .For example,X X X

今天下午看到一题关于二维数组顺时针打印，感觉第二部的方法书中解释的有点脱离带水的意思，所以自己实现了一下，基本思想如下：其实题目就是安圈来一层一层的打印，所以每次圈的起点为二维数组对称轴上的数，并且由于每一圈的结束，二维数组的行和列的数是减二，所以结束条件就是：行package str;import java.util.Vector;public class PrintMatr

Question :Given a string containing only digits, restore it by returning all possible valid IP address combinations.For example:Given "25525511135",return ["255.255.11.135", "255.255.111

题目：Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.For example, Given [0,1,0,2,1,0,1,3

今天特地把快速算法用Java实现了一下，毕竟找工作面试笔试用的比较多。package String.Cheng;import java.util.Scanner;public class QuickSort { public static void Swap(int []s,int l,int r){ int temp; if (s[l]<s[r]&&s[r]<s[(l+r)

这一题用动态规划的思想解决的，算法时间复杂度和空间复杂度都不太好，不过动态规划的思路基本都是这样的。如果求和最大字数组，同样可以对所有字数组进行叠加判断，不过最好在算法中改进一下，可以减少算法计算量。package text;import java.util.ArrayList;import java.util.Arrays;import java.util.List;/** * PD