Coin change 2

class Solution {
public:
    int change(int amount, vector<int>& coins) {
	vector<int> dp(amount+1,0);
	dp[0]=1;
	for(int c:coins)
	{
		for(int i=c;i<=amount;i++)
			dp[i]+=dp[i-c];
	}
	return dp[amount];
}
};