feat: add swift implementation to lcof2 problem: No.075 (#3409)

Author: klever34

lcof2/剑指 Offer II 075. 数组相对排序/README.md

@@ -167,6 +167,38 @@ class Solution:
         return arr1
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func relativeSortArray(_ arr1: [Int], _ arr2: [Int]) -> [Int] {
+        var frequency = [Int](repeating: 0, count: 1001)
+        var result = [Int]()
+        
+        for num in arr1 {
+            frequency[num] += 1
+        }
+        
+        for num in arr2 {
+            while frequency[num] > 0 {
+                result.append(num)
+                frequency[num] -= 1
+            }
+        }
+        
+        for num in 0..<frequency.count {
+            while frequency[num] > 0 {
+                result.append(num)
+                frequency[num] -= 1
+            }
+        }
+        
+        return result
+    }
+}
+
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 075. 数组相对排序/Solution.swift

@@ -0,0 +1,26 @@
+class Solution {
+    func relativeSortArray(_ arr1: [Int], _ arr2: [Int]) -> [Int] {
+        var frequency = [Int](repeating: 0, count: 1001)
+        var result = [Int]()
+        
+        for num in arr1 {
+            frequency[num] += 1
+        }
+        
+        for num in arr2 {
+            while frequency[num] > 0 {
+                result.append(num)
+                frequency[num] -= 1
+            }
+        }
+        
+        for num in 0..<frequency.count {
+            while frequency[num] > 0 {
+                result.append(num)
+                frequency[num] -= 1
+            }
+        }
+        
+        return result
+    }
+}