/**
knakul853
**/
class Solution {
public:
    int change(int amount, vector<int>& coins) {

        vector<int>dp(amount+1);
        dp[0] = 1;

        for( int coin : coins )
        {
            for( int j=coin; j<=amount; j++ )
            {
                dp[j] += dp[j-coin];
            }
        }

        return dp[amount];

    }
};