算法01

//第2章的算法实现题
#include<iostream>
#include<vector>
#include<algorithm>
#include"demo01.h"


//2-1  重数问题
void test01(std::vector<int>& v)
{
	auto iter = adjacent_find(v.begin(),v.end());     //返回第一次重复的元素迭代器
	int num = std::count(v.begin(), v.end(), *iter); //找重复元素的个数
	std::cout << "重数为：" << *iter << std::endl;
	std::cout << "出现的次数为： " << num << std::endl;
}

//2-2


//2-3
int test03(int n)
{
	int res;
	if (n == 1) return 1;
	if (n == 2) return 2;
	if (n % 2 != 0)    //奇数时
	{
		res = test03(n - 1);
	}
	else
		res = test03(n - 2) + test03(n / 2);
	return res;
}

//2-8集合划分问题
int test08(int n,int m)
{
	if (m == 1) return 1;
	if (n == m) return 1;
	else
		return test08(n - 1, m - 1) + test08(n - 1, m)*m;

}

//2-10
unsigned long long c[25];
void test10()
{
	int i, j;
	c[1] = 1;
	for (i = 2; i <= 20; i++)
		c[i] = c[i - 1] * (4 * i - 2) / (i + 1);
}

int main()
{
	//std::cout << "liujiepeng demo 01" << std::endl;

	//int a[10] = { 1,2,3,4,5,6,7,8,9,90 };
	//int res = BinarySearch4(a, 4, 10);
	//std::cout << res << std::endl;

	std::vector<int> v;
	v.push_back(6);
	v.push_back(1);
	v.push_back(2);
	v.push_back(2);
	v.push_back(2);
	v.push_back(3);
	v.push_back(5);
	//test01(v);

	/*int num = test03(6);
	std::cout << num << std::endl;*/

	/*int num = test08(4, 3);
	std::cout << num << std::endl;*/
	int n;
	std::cin >> n;
	std::cout << c[n];


	system("pause");
	return 0;
}