lxf310的专栏

转载自：http://blog.unieagle.net/2012/11/01/leetcode%E9%A2%98%E7%9B%AE%EF%BC%9Aunique-binary-search-trees%EF%BC%8C%E4%B8%80%E7%BB%B4%E5%8A%A8%E6%80%81%E8%A7%84%E5%88%92/用一维动态规划解。Sigma(左边的子树可能状态 * 右边

转载自：http://blog.chinaunix.net/uid-11775320-id-3143919.html1.    HashMap概述   HashMap是基于哈希表的Map接口的非同步实现。此实现提供所有可选的映射操作，并允许使用null值和null键。此类不保证映射的顺序，特别是它不保证该顺序恒久不变。 2.    HashMap的数据结构   在java编

转载自：http://hawstein.com/posts/dp-novice-to-advanced.html

转载自：http://blog.youkuaiyun.com/killua_hzl/article/details/7444864【题目描述】两个数组a[N]，b[N]，其中A[N]的各个元素值已知，现给b[i]赋值，b[i] = a[0]*a[1]*a[2]...*a[N-1]/a[i]；要求：1.不准用除法运算2.除了循环计数值，a[N],b[N]外，不准再用其他任何变

转载自：http://blog.youkuaiyun.com/arhaiyun/article/details/119839132012创新工场校园招聘的一道编程算法题：马戏团里有个叠罗汉的表演，为了便于美观，下面的人身高和体重都要大于上面的人。现在知道n个演员的身高和体重，请问最多能叠多少层？设计思路：首先生成一个有向图map，用连接矩阵的方式来表示。map[i][j]==1表示

给定一个单链表，只给出头指针h：1、如何判断是否存在环？2、如何知道环的长度？3、如何找出环的连接点在哪里？4、带环链表的长度是多少？ 解法：1、对于问题1，使用追赶的方法，设定两个指针slow、fast，从头指针开始，每次分别前进1步、2步。如存在环，则两者相遇；如不存在环，fast遇到NULL退出。2、对于问题2，记录下问题1的碰

转载自：http://cooker.iteye.com/blog/969196//MD5.h #ifndef BZF_MD5_H#define BZF_MD5_H#include #include // a small class for calculating MD5 hashes of strings or byte arrays// it

首先我们可以分析人们是如何做十进制的加法的，比如是如何得出5+17=22这个结果的。实际上，我们可以分成三步进行：第一步只做各位相加不进位，此时相加的结果是12（个位数5和7相加不要进位是2，十位数0和1相加结果是1）；第二步做进位，5+7中有进位，进位的值是10;第三步把前面两个结果加起来，12+10的结果是22，刚好5+17=22。我们一直在想，求两数之和四则运算都不能用，那还能用什么？对

Description:You are given two sorted list of numbers(ascending order). The lists themselves are comma delimited and the two lists are semicolon delimited. Print out the intersection of these two s

Description:You are given a sorted array of positive integers and a number 'X'. Print out all pairs of numbers whose sum is equal to X. Print out only unique pairs and the pairs should be in ascen

Description:Flavius Josephus was a famous Jewish historian of the first century, at the time of the destruction of the Second Temple. According to legend, during the Jewish-Roman war he was trap

Description:A double-square number is an integer X which can be expressed as the sum of two perfect squares. For example, 10 is a double-square because 10 = 3^2 + 1^2. Your task in this problem

Description:You are given a prefix expression. Write a program to evaluate it.Input sample:The first argument will be an input file with one prefix expression per line. e.g.* + 2 3 4

Description:A number is a self-describing number when (assuming digit positions are labeled 0 to N-1), the digit in each position is equal to the number of times that that digit appears in the num

Description:Write a program to determine the lowest common ancestor of two nodes in a binary search tree. You may hardcode the following binary search tree in your program: 30 | ___

Description:Write a program to print out all the permutations of a string in alphabetical order.Input sample:The first argument will be a text file containing an input string, one per line

Description:Write a program to read a multiple line text file and write the 'N' longest lines to stdout. Where the file to be read is specified on the command line.Input sample:Your progra

在Java中，就是类A调用类B中的某个方法b，然后类B又在某个时候反过来调用类A中的某个方法a，对于A来说，这个a方法便叫做回调方法pubilc interface CallBack{ public void callbackMethod(); } public class A implements CallBack{ //