# 0518. Coin Change 2
###### tags: `Leetcode` `Medium` `Dynamic Programming`
Link: https://leetcode.com/problems/coin-change-2/
## 思路
不能算是一个完全背包问题
因为不是求总价值的最优
而是单纯求组合数

## Code

class Solution {
public int change(int amount, int[] coins) {
int n = coins.length;
int[] dp = new int[amount+1];
dp[0] = 1;
for(int i=0; i<n; i++){
for(int j=0; j<=amount; j++){
if(j>=coins[i]){
dp[j] += dp[j-coins[i]];
}
}
}
return dp[amount];
}
}