How Many Trees? Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)Total Submission(s): 3952    Accepted Submission(s): 2238 Problem Description A binary search tree is a binary tree with root k such that any node v re…

How Many Trees? Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 3317    Accepted Submission(s): 1922 Problem Description A binary search tree is a binary tree with root k such that any node v r…

裸的卡特兰数 C++#include<iostream> #include<cstdio> using namespace std; #define base 10000 #define len 100 void multiply(int a[],int max,int b) { ; ;i>=;i--) { array+=b*a[i]; a[i]=array%base; array/=base; } } void divide(int a[],int max,int b) {…

题目 题意:给你一个数字n,问你将1~n这n个数字,可以组成多少棵不同的二叉搜索树. 1,2,5,14--根据输出中的规律可以看出这是一个卡特兰数的序列.于是代用卡特兰数中的一个递推式: 因为输入可取到100,用无符号位计算最高可计算33个卡特兰数,所以可以用java中的大数 import java.math.BigInteger; import java.util.Scanner; public class Main { public static void main(String[] arg…

[题目链接]http://acm.hdu.edu.cn/showproblem.php?pid=1134 [解题背景]这题不会做,自己推公式推了一段时间,将n=3和n=4的情况列出来了,只发现第n项与第n-1项有关系,上网搜索的时候发现是组合数学中关于Catalan(卡特兰)数的运用. 以下资料来自网络,整理以备记录学习: [来源链接] http://baike.baidu.com/view/2499752.htm http://blog.163.com/lz_666888/blog/stati…

题目:http://acm.hdu.edu.cn/showproblem.php?pid=1693 第一道插头 DP ! 直接用二进制数表示状态即可. #include<cstdio> #include<cstring> #include<algorithm> #define ll long long using namespace std; ,M=(<<)+; int n,m,bin[N];ll dp[N][N][M]; int b[N][N]; void…

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…

Surround the Trees Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10803    Accepted Submission(s): 4187 Problem Description There are a lot of trees in an area. A peasant wants to buy a rope t…

Surround the Trees:http://acm.hdu.edu.cn/showproblem.php?pid=1392 题意: 在给定点中找到凸包,计算这个凸包的周长. 思路: 这道题找出凸包上的点后,s数组中就是按顺序的点,累加一下距离就是周长了. #include <algorithm> #include <iterator> #include <iostream> #include <cstring> #include <cstdli…

题目链接:HDU 1392 Problem Description There are a lot of trees in an area. A peasant wants to buy a rope to surround all these trees. So at first he must know the minimal required length of the rope. However, he does not know how to calculate it. Can you…