Facebook Hacker Cup 2014 Qualification Round比赛Square Detector题的解题报告.单击这里打开题目链接(国内访问需要那个,你懂的). 原题如下: Square Detector Problem Description You want to write an image detection system that is able to recognize different geometric shapes. In the first ver…

2014 Qualification Round Solutions 2013年11月25日下午 1:34 ...最简单的一题又有bug...自以为是真是很厉害! 1. Square Detector (20 Points) When facing a problem in a programming contest there are three main things to consider when planning your solution. In order of importanc…

题目地址:http://blog.csdn.net/shiyuankongbu/article/details/10004443 /* 题意:在i前面找回文子串,在i后面找回文子串相互配对,问有几对 DP:很巧妙的从i出发向两头扩展判断是否相同来找回文串 dpr[i] 代表记录从0到i间的回文子串的个数,dpl[i] 代表记录i之后的回文子串个数 两两相乘就行了 详细解释:http://blog.csdn.net/shiyuankongbu/article/details/10004443 */…

1182 完美字符串             题目来源:                         Facebook Hacker Cup选拔         基准时间限制:1 秒 空间限制:131072 KB 分值: 5         难度:1级算法题 约翰认为字符串的完美度等于它里面所有字母的完美度之和.每个字母的完美度可以由你来分配,不同字母的完美度不同,分别对应一个1-26之间的整数. 约翰不在乎字母大小写.(也就是说字母F和f)的完美度相同.给定一个字符串,输出它的最大可能的完…

原标题:https://www.facebook.com/hackercup/problems.php?pid=759650454070547&round=344496159068801 题意:给定一颗有根树,在树上下层的节点要给上层节点礼物,根节点的礼物则给慈善会,可是给礼物有个条件就是你不能送你的父节点已经送出的礼物.问满足要求的最少花费. 题解:这个题卡了一段时间,相似于染色问题,能够用树形动态规划求解.由于已知节点个数为N,则我们单个节点的最大花费不会超过log2(N) = 18. 1.…

原题:pid=688426044611322&round=344496159068801">https://www.facebook.com/hackercup/problems.php?pid=688426044611322&round=344496159068801 题意:你和一个朋友玩足球游戏,分数从0-0開始,终于你总是赢.而且你主要有两种方式赢,第一种stressFree方式你肯定要进第一个球而且总是比你的朋友分数高,另外一种stressFull方式除了你的朋友达…

题意:给定A,B,K(A<=B)三个数,问在[A,B]范围内的数素数因子个数为K的个数. 题解:典型的筛选法求素数.首先建立一个保存素数因子个数的数组factorNum[],以及到n为止含有素数因子个数为k的二维数组sumNum[n][k]. factorNum能够由筛选法确定.初始化数组为0. 1. 从小到大遍历给定最大范围内的数,若遍历到数n时,factorNum[n]=0则说明这个数是素数(前面没有它的因子). 2. 然后通过添加n的倍数,来筛选出最大范围内含有素数因子n的数. sumNu…

C. Cd and pwd commands Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/158/C Description Vasya is writing an operating system shell, and it should have commands for working with directories. To begin with, he dec…

C. String Manipulation 1.0 Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 codeforces.com/problemset/problem/91/B Description One popular website developed an unusual username editing procedure. One can change the username only by deleting some characte…

Cd and pwd commands time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output Vasya is writing an operating system shell, and it should have commands for working with directories. To begin with, he…