feat: add swift implementation to lcof2 problem: No.103 (doocs#3616)

Author: klever34

lcof2/剑指 Offer II 103. 最少的硬币数目/README.md

@@ -169,6 +169,26 @@ var coinChange = function (coins, amount) {
 };
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func coinChange(_ coins: [Int], _ amount: Int) -> Int {
+        var dp = [Int](repeating: amount + 1, count: amount + 1)
+        dp[0] = 0
+
+        for coin in coins {
+            if coin > amount { continue }
+            for j in coin...amount {
+                dp[j] = min(dp[j], dp[j - coin] + 1)
+            }
+        }
+
+        return dp[amount] > amount ? -1 : dp[amount]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 103. 最少的硬币数目/Solution.swift

@@ -0,0 +1,15 @@
+class Solution {
+    func coinChange(_ coins: [Int], _ amount: Int) -> Int {
+        var dp = [Int](repeating: amount + 1, count: amount + 1)
+        dp[0] = 0  
+
+        for coin in coins {
+            if coin > amount { continue }
+            for j in coin...amount {
+                dp[j] = min(dp[j], dp[j - coin] + 1)
+            }
+        }
+
+        return dp[amount] > amount ? -1 : dp[amount]
+    }
+}