题目代号:HDU 1134 题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1134 Game of Connections Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4668    Accepted Submission(s): 2729 Problem Description Thi…

How Many Trees? Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 3382    Accepted Submission(s): 1960 Problem Description A binary search tree is a binary tree with root k such that any node v re…

题目链接 分析:打表以后就能发现时卡特兰数, 但是有除法取余. f[i] = f[i-1]*(4*i - 2)/(i+1); 看了一下网上的题解,照着题解写了下面的代码,不过还是不明白,为什么用扩展gcd, 不是用逆元吗.. 网上还有别人的解释,没看懂,贴一下: (a / b) % m = ( a % (m*b)) / b 笔者注:鉴于ACM题目特别喜欢M=1000000007,为质数: 当gcd(b,m) = 1, 有性质: (a/b)%m = (a*b^-1)%m, 其中b^-1是b模m的逆…

Problem Description The "Harry Potter and the Goblet of Fire" will be on show in the next few days. As a crazy fan of Harry Potter, you will go to the cinema and have the first sight, won't you? Suppose the cinema only has one ticket-office and…

主要考察卡特兰数,大数乘法,除法…… 链接http://acm.hdu.edu.cn/showproblem.php?pid=1134 #include<iostream>#include<stdio.h>#include<algorithm>#include<cmath>#include<iomanip>;}…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=1133 题目的意思是,m个人只有50元钱,n个人只有100元整钱,票价50元/人.现在售票厅没钱,只有50元钱的人可以不用找钱顺利买票,而拿着100元整钱的人只有在前面有50元的情况下才能买票,因为只有这样,才能找零50元.所有的人能否买票和排队的方式有一定关系,问使得所有的人能够顺利买票的排队方式有多少种? 上述问题可以抽象为下面的数学模型,数学模型及求解过程如下图: 本题中每个人是不一样的,所以本题的…

Game of Connections Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 9128   Accepted: 4471 Description This is a small but ancient game. You are supposed to write down the numbers 1, 2, 3, . . . , 2n - 1, 2n consecutively in clockwise ord…

题意: 给出一个数字n,假设火车从1~n的顺序分别进站,求有多少种出站序列. 思路: 卡特兰数的经典例子.n<101,用递推式解决.需要使用到大数.n=100时大概有200位以下. #include <bits/stdc++.h> using namespace std; ; vector<string> vect; void _mult(string num1, string num2, string &result ) { reverse(num1.begin()…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 7539    Accepted Submission(s): 4062 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Stat…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1130 卡特兰数:https://blog.csdn.net/qq_33266889/article/details/53409553 参考文章:https://blog.csdn.net/sunshine_YG/article/details/47685737 #include<iostream> #include<cstdio> #include<cstring> usi…