feat: add swift implementation to lcof2 problem: No.104 (#3617)

Author: klever34

lcof2/剑指 Offer II 104. 排列的数目/README.md

@@ -141,6 +141,27 @@ func combinationSum4(nums []int, target int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func combinationSum4(_ nums: [Int], _ target: Int) -> Int {
+        var dp = [Int](repeating: 0, count: target + 1)
+        dp[0] = 1
+
+        for i in 1...target {
+            for num in nums {
+                if i >= num, dp[i] <= Int.max - dp[i - num] {
+                    dp[i] += dp[i - num]
+                }
+            }
+        }
+
+        return dp[target]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 104. 排列的数目/Solution.swift

@@ -0,0 +1,16 @@
+class Solution {
+    func combinationSum4(_ nums: [Int], _ target: Int) -> Int {
+        var dp = [Int](repeating: 0, count: target + 1)
+        dp[0] = 1
+        
+        for i in 1...target {
+            for num in nums {
+                if i >= num, dp[i] <= Int.max - dp[i - num] {
+                    dp[i] += dp[i - num]
+                }
+            }
+        }
+
+        return dp[target]
+    }
+}