F_G

摘要： 这道题目实际上有非常好的O（N^2)的解法。关键是利用了2sum的线性解法public class Solution { public List> threeSum(int[] nums) { List> res = new LinkedList>(); if(nu... 阅读全文

摘要： 数字表示为链表的格式，需要注意的几个地方：一、在计算过程当中要注意进位问题，刚开始的进位为0，后面进位要在计算过程当中进行更新。二、如果某个数字的list比较长，那么需要在最后将其加上三、最后如果进位不是零，说明需要额外增加一位代码如下： 1 /** 2 * Definition for sing... 阅读全文

摘要： 1 import java.util.*; 2 3 public class Solution { 4 public int[] twoSum(int[] nums, int target) { 5 Map map = new HashMap(); 6 i... 阅读全文

摘要： The problem is well known, so there is no need to repeat it!we can apply the iteration function f(n+1) = f(n)+f(n-1), however the time complexity is O... 阅读全文

摘要： method 1: permutation !method 2: use integer and select element according to the bit in each integer. 阅读全文

摘要： crute method is RE!! 阅读全文

摘要： 1. From the last index, we seach the first decrease order, such i,i+1 and num[i] 14532 -> 14235The last step is to change the order from 5 to 2 to be ... 阅读全文

摘要： The difference betweent Problem Permutation I and Permuation II lies in the duplicates elements may exist in the second one.For the first one , the en... 阅读全文

摘要： I have two solutions for this problem, the first one is from the undergraduate stage, the second one is from the CTCI (permute string)The common point... 阅读全文

摘要： MySQL当中的限制条件可以使用on或者where，两者在不同的情况下具有不同而意义如果是left join on，这里的on是对右表的限制，对左表没有限制如果是inner join on/where意思是一样的[1]http://www.jb51.net/article/39814.htm 阅读全文