【问题】

想兑换100元钱，有1,2,5,10四种钱，问总共有多少兑换方法。

const int N = 100;
int dimes[] = {1, 2, 5, 10};
int arr[N+1] = {1};
int coinExchange(int n)  //动态规划
{
	int i, j;
	for (i = 0; i < sizeof(dimes)/sizeof(int); i++) {
		for (j = dimes[i]; j <= n; j++) 
			arr[j] += arr[j-dimes[i]];
	}
	return arr[n];
}

int coinExchangeRecursion(int n, int m) //递归
{
	if (n == 0)
		return 1;
	if (n < 0 || m == 0)
		return 0;
	return (coinChangeRecursion(n, m-1) + coinChangeRecursion(n-dimes[m-1], m));
}