题意: 给你一个数n,表示有n辆火车,编号从1到n,入站,问你有多少种出站的可能.    (题于文末) 知识点: ps:百度百科的卡特兰数讲的不错,注意看其参考的博客. 卡特兰数(Catalan):前几项为 : 1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900, 2674440, 9694845, 35357670- 令h(0)=1,h(1)=1,catalan数满足递推式:      h(n)= h(0…

题目链接_HDU-1023 题目 As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the trains can get out of the railway. input The input contains sever…

题目链接:https://cn.vjudge.net/problem/HDU-1023 题意 卡特兰数的应用之一 求一个长度为n的序列通过栈后的结果序列有几种 思路 一开始不知道什么是卡特兰数,猜测是一个递推题 注意到在序列第i个元素入栈时,前几个元素都进过栈,就是通过栈的操作 设n个元素通过栈的结果序列个数为h[n],则有: \[ h_n=h_1h_{n-1}+h_2h_{n-2}+...+h_{n-1}h_1 \] 查了以后发现这是卡特兰数的规律,有通项: \[ h_n=h_{n-1}\fr…

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()…

火车进站出站的问题满足卡特兰数...卡特兰数的相关知识如下: 卡特兰数又称卡塔兰数,是组合数学中一个常出现在各种计数问题中出现的数列.由以比利时的数学家欧仁·查理·卡塔兰 (1814–1894)命名. 前几项为 (OEIS中的数列A000108): 1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, 58786, 208012, 742900, 2674440, 9694845, 35357670, 129644790, 477638700, 176…

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…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 4358    Accepted Submission(s): 2391 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Stati…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=1023 Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 12035    Accepted Submission(s): 6422 Problem Description As we all know the…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10372    Accepted Submission(s): 5543 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Sta…

题目连接 http://acm.hdu.edu.cn/showproblem.php?pid=1212 Train Problem II Description As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the t…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 9701    Accepted Submission(s): 5210 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Stat…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 7918    Accepted Submission(s): 4241 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Stati…

Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the trains can get out of the railway.   Input The input contains…

Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the trains can get out of the railway.   Input The input contains…

卡特兰数: Catalan数 原理: 令h(1)＝1,h(0)=1,catalan数满足递归式: h(n)= h(1)*h(n-1) + h(2)*h(n-2) + ... + h(n-1)h(1) (其中n>=2) 另类递归式: h(n)=((4*n-2)/(n+1))*h(n-1); 该递推关系的解为: h(n+1)=C(2n,n)/(n+1) (n=1,2,3,...) 最典型的四类应用:(实质上却都一样,无非是递归等式的应用,就看你能不能分解问题写出递归式了) 1.括号化问题. 矩阵链乘…

链接:传送门 题意:裸卡特兰数,但是必须用大数做 balabala:上交高精度模板题,增加一下熟悉度 /************************************************************************* > File Name: hdu1023.cpp > Author: WArobot > Blog: http://www.cnblogs.com/WArobot/ > Created Time: 2017年05月11日 星期四 19…

问题陈述: HDOJ Problem - 1023 问题解析: 卡特兰数(Catalan)的应用 基本性质: f(n) = f(1)f(n-1) + f(2)f(n-2) + ... + f(n-2)f(2) + f(n-1)f(1); f(n) = C(2n, n) / (n+1) = C(2n-2, n-1) / n;  Cn = (4n-2)/(n+1) Cn-1 代码详解: I: C++ #include <iostream> #include <cstdio> #incl…

Description As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing order, how many orders that all the trains can get out of the railway. Input The input contains several te…

一个出栈有多少种顺序的问题.一般都知道是Catalan数了. 问题是这个Catalan数非常大,故此须要使用高精度计算. 并且打表会速度快非常多.打表公式要熟记: Catalan数公式 Cn=C(2n,n) / (n+1); 递推公式 C(n ) = C(n-1)*(4*n-2) / (n+1) 高精度乘以一个整数和高精度除以一个整数的知识.这样还是使用整数数组比較好计算,假设使用string那么就不太好计算了,由于整数也可能是多位的. const int MAX_N = 101; short…

题目链接: http://acm.hdu.edu.cn/showproblem.php?pid=1023 题目大意: 一列N节的火车以严格的顺序到一个站里.问出来的时候有多少种顺序. 解题思路: 典型的求Catalan数的题目,可是结果会非常大,所以须要用大数来解决. Catalan公式为 h(n) = h(n-1) * (4*n-2) / (n + 1),h(0) = h(1) = 1. AC代码: #include<iostream> #include<algorithm> #…

考虑第1个火车出站的时刻,从1到n都有可能,如果它是第i个出栈,那么前面有规模为i-1的子问题,后面有规模为n-i的子问题.累加.…

Train Problem II Time Limit: 1000MS   Memory Limit: 32768KB   64bit IO Format: %I64d & %I64u Submit Status Description As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasing…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Station want to know if all the trains come in strict-increasi…

地址:http://acm.hdu.edu.cn/showproblem.php?pid=1023 题目: Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 7675    Accepted Submission(s): 4131 Problem Description As we all know the…

Train Problem II Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 5372    Accepted Submission(s): 2911 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Stati…

Tree Maker Problem Description Tree Lover loves trees crazily. One day he invents an interesting game which is named Tree Maker. In this game, all trees are binary trees. Initially, there is a tree with only one vertex and a cursor on it. Tree Lover…

Brackets Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)Total Submission(s): 659    Accepted Submission(s): 170 Problem Description We give the following inductive definition of a “regular brackets” sequence: ● the…

http://acm.csu.edu.cn/OnlineJudge/problem.php?id=1320 题意:……是舀的时候里面必须要有1L,而不是舀完必须要有1L. 思路:才知道是卡特兰数. 这个感觉写的很好 http://www.cnblogs.com/wuyuegb2312/p/3016878.html 卡特兰数可以解决:求括号匹配,出栈入栈等组合个数的问题. 卡特兰数公式:first O(n): h(n) = h(n-1) * (4*n-2) / (n+1)second O(n^2)…

链接: https://vjudge.net/problem/LightOJ-1170 题意: BST is the acronym for Binary Search Tree. A BST is a tree data structure with the following properties. i) Each BST contains a root node and the root may have zero, one or two children. Each of the chi…

1170 - Counting Perfect BST BST is the acronym for Binary Search Tree. A BST is a tree data structure with the following properties. i)        Each BST contains a root node and the root may have zero, one or two children. Each of the children themsel…