README.md

518. Coin Change 2

You are given coins of different denominations and a total amount of money. Write a function to compute the number of combinations that make up that amount. You may assume that you have infinite number of each kind of coin.

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 

Note:

You can assume that

• 0 <= amount <= 5000
• 1 <= coin <= 5000
• the number of coins is less than 500
• the answer is guaranteed to fit into signed 32-bit integer

Solutions (Rust)

1. Dynamic Programming

implSolution{pubfnchange(amount:i32,coins:Vec<i32>) -> i32{letmut dp = vec![0; amount asusize + 1]; dp[0] = 1;for&coin in&coins {for i in(coin asusize)..=(amount asusize){ dp[i] += dp[i - coin asusize];}} dp[amount asusize]}}