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…

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 */…

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…

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…

题目链接:http://codeforces.com/contest/158/problem/E E. Phone Talks time limit per test 3 seconds memory limit per test 256 megabytes input standard input output standard output Cool J has recently become a businessman Mr. Jackson, and he has to make a l…

今天在codeforces上面做到一道题:http://codeforces.com/contest/638/problem/B 题目大意是:给定n个字符串,找到最短的字符串S使得n个字符串都是这个字符串S的子串. 题目里有一个限制条件是每个字母都最多出现一次,所以可以用下面的方法来解决: http://codeforces.com/contest/638/submission/16900955 然后我想到如果问题没有“每个字母最多只出现一次”这个限制的话应该怎么解决. 暂时还在想………

题目链接: http://codeforces.com/problemset/problem/522/D D. Closest Equals time limit per test3 secondsmemory limit per test256 megabytes 问题描述 You are given sequence a1, a2, ..., an and m queries lj, rj (1 ≤ lj ≤ rj ≤ n). For each query you need to print…

D. Three-dimensional Turtle Super Computer 题目连接: http://www.codeforces.com/contest/638/problem/D Description A super computer has been built in the Turtle Academy of Sciences. The computer consists of n·m·k CPUs. The architecture was the paralellepip…

C. Road Improvement 题目连接: http://www.codeforces.com/contest/638/problem/C Description In Berland there are n cities and n - 1 bidirectional roads. Each road connects some pair of cities, from any city you can get to any other one using only the given…

B. Making Genome in Berland 题目连接: http://www.codeforces.com/contest/638/problem/B Description Berland scientists face a very important task - given the parts of short DNA fragments, restore the dinosaur DNA! The genome of a berland dinosaur has notin…