B. A Trivial Problem 题目连接: http://www.codeforces.com/contest/633/problem/B Description Mr. Santa asks all the great programmers of the world to solve a trivial problem. He gives them an integer m and asks for the number of positive integers n, such t…

数学技巧真有趣,看出规律就很简单了 wa 题意:给出数k  输出所有阶乘尾数有k个0的数 这题来来回回看了两三遍, 想的方法总觉得会T 后来想想  阶乘 emmm  1*2*3*4*5*6*7*8*9*10...*n 尾数的0只与5有关 是5的几倍就有几个0  因为5前面肯定有偶数 乘起来就有一个0 而且最后输出肯定是连续的5个 hhh 兴奋 开始上手 乱搞一下  发现复杂度还行 测样例 发现 k=5 的时候不对了 输出25~29了 应该是0的 咦  测了一下 25!应该是6个0的 25=5*5…

B. A Trivial Problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mr. Santa asks all the great programmers of the world to solve a trivial problem. He gives them an integer m and asks f…

暴力 A - Ebony and Ivory import java.util.*; import java.io.*; public class Main { public static void main(String[] args) { Scanner cin = new Scanner (new BufferedInputStream (System.in)); int a = cin.nextInt (); int b = cin.nextInt (); int c = cin.nex…

B. A Trivial Problem time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Mr. Santa asks all the great programmers of the world to solve a trivial problem. He gives them an integer m and asks f…

题目链接:http://codeforces.com/problemset/problem/633/G 大意是一棵树两种操作,第一种是某一节点子树所有值+v,第二种问子树中节点模m出现了多少种m以内的质数. 第一种操作非常熟悉了,把每个节点dfs过程中的pre和post做出来,对序列做线段树.维护取模也不是问题.第二种操作,可以利用bitset记录质数出现情况.所以整个线段树需要维护bitset的信息. 对于某一个bitset x,如果子树所有值需要加y,则x=(x<<y)|(x>>…

题目链接:http://codeforces.com/problemset/problem/633/C 大意就是给个字典和一个字符串,求一个用字典中的单词恰好构成字符串的匹配. 比赛的时候是用AC自动机写的,就是对于trie中每一个节点,判断是否为终结点,以及当前字符所在位置p减去trie中这个节点的深度也即某一单词的长度l,判断dp[p-l]是否可以被构成,可以的话直接break并且标记当前dp值. 赛后想了想,其实直接一个trie就行了,每个单词才1000的长度,又想起来我去年给人讲过类似的…

H. Fibonacci-ish II 题目连接: http://codeforces.com/contest/633/problem/H Description Yash is finally tired of computing the length of the longest Fibonacci-ish sequence. He now plays around with more complex things such as Fibonacci-ish potentials. Fibo…

E. Startup Funding 题目连接: http://codeforces.com/contest/633/problem/E Description An e-commerce startup pitches to the investors to get funding. They have been functional for n weeks now and also have a website! For each week they know the number of u…

G. Yash And Trees 题目连接: http://www.codeforces.com/contest/633/problem/G Description Yash loves playing with trees and gets especially excited when they have something to do with prime numbers. On his 20th birthday he was granted with a rooted tree of…