0322-coin-change.swift

/**
 * Question Link: https://leetcode.com/problems/coin-change/
 */

 class Solution {
    func coinChange(_ coins: [Int], _ amount: Int) -> Int {
        var dp = [Int](repeating: amount + 1, count: amount + 1)
        dp[0] = 0
        for a in 1..<amount + 1 {
            for c in coins {
                if a - c >= 0 {
                    dp[a] = min(dp[a], (1 + dp[a - c]))
                }
            }
        }
        return dp[amount] != amount + 1 ? dp[amount] : -1   
    }
}