You are given an integer array `coins` representing coins of different denominations and an integer `amount` representing a total amount of money.

Return the number of combinations that make up that amount. If that amount of money cannot be made up by any combination of the coins, return `0`.

You may assume that you have an infinite number of each kind of coin.

The answer is guaranteed to fit into a signed 32-bit integer.

Example 1:

    Input: amount = 5, coins = [1,2,5]
    Output: 4
    Explanation: there are four ways to make up the amount:
    5=5
    5=2+2+1
    5=2+1+1+1
    5=1+1+1+1+1

Example 2:

    Input: amount = 3, coins = [2]
    Output: 0
    Explanation: the amount of 3 cannot be made up just with coins of 2.

Example 3:

    Input: amount = 10, coins = [10]
    Output: 1

Constraints:

- `1 <= coins.length <= 300`
- `1 <= coins[i] <= 5000`
- All the values of `coins` are unique.
- `0 <= amount <= 5000`