C++ 找零钱方法数

* 动态规划法

#include "stdafx.h"
#include <iostream>
#include <vector>

using std::vector;

class Solution {
public:
	static int coins(vector<int> deno, int v) {
		if (deno.size() == 0 || v < 0) {
			return 0;
		}
		vector<int> dp = vector<int>(v + 1, 0);
		for (int j = 0; deno[0] * j <= v; j++) {
			dp[deno[0] * j] = 1;
		}
		for (int i = 1; i < deno.size(); i++) {
			for (int j = 1; j <= v; j++) {
				dp[j] += j - deno[i] >= 0 ? dp[j - deno[i]] : 0;
			}
		}
		return dp[v];
	}
};

int main()
{
	vector<int> deno = { 50, 20, 10, 5, 1 };
	Solution sln;
	int solutions = sln.coins(deno, 100);
	std::cout << solutions << "\n";
	getchar();

    return 0;
}

　　343

* 数学问题

   maths is fun

   https://www.mathsisfun.com/algebra/index.html