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.…

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…

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): 4358    Accepted Submission(s): 2391 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…

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()…

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…

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…

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): 9701    Accepted Submission(s): 5210 Problem Description As we all know the Train Problem I, the boss of the Ignatius Train Stat…