feat: add swift implementation to lcof2 problem: No.074 (#3307)

Author: klever34

lcof2/剑指 Offer II 074. 合并区间/README.md

@@ -188,6 +188,32 @@ public class Solution {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func merge(_ intervals: [[Int]]) -> [[Int]] {
+        guard !intervals.isEmpty else { return [] }
+
+        let intervals = intervals.sorted { $0[0] < $1[0] }
+        var result: [[Int]] = []
+
+        var currentInterval = intervals[0]
+        for interval in intervals.dropFirst() {
+            if currentInterval[1] < interval[0] {
+                result.append(currentInterval)
+                currentInterval = interval
+            } else {
+                currentInterval[1] = max(currentInterval[1], interval[1])
+            }
+        }
+        result.append(currentInterval)
+
+        return result
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 074. 合并区间/Solution.swift

@@ -0,0 +1,21 @@
+class Solution {
+    func merge(_ intervals: [[Int]]) -> [[Int]] {
+        guard !intervals.isEmpty else { return [] }
+        
+        let intervals = intervals.sorted { $0[0] < $1[0] }
+        var result: [[Int]] = []
+        
+        var currentInterval = intervals[0]
+        for interval in intervals.dropFirst() {
+            if currentInterval[1] < interval[0] {
+                result.append(currentInterval)
+                currentInterval = interval
+            } else {
+                currentInterval[1] = max(currentInterval[1], interval[1])
+            }
+        }
+        result.append(currentInterval)
+        
+        return result
+    }
+}