feat: add swift implementation to lcof problem: No.57.2 (doocs#2947)

Author: klever34

lcof/面试题57 - II. 和为s的连续正数序列/README.md

@@ -211,6 +211,35 @@ public class Solution {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func findContinuousSequence(_ target: Int) -> [[Int]] {
+        var l = 1, r = 2
+        var result = [[Int]]()
+        
+        while l < r {
+            let sum = (l + r) * (r - l + 1) / 2
+            if sum == target {
+                var sequence = [Int]()
+                for i in l...r {
+                    sequence.append(i)
+                }
+                result.append(sequence)
+                l += 1
+            } else if sum < target {
+                r += 1
+            } else {
+                l += 1
+            }
+        }
+        
+        return result
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof/面试题57 - II. 和为s的连续正数序列/Solution.swift

@@ -0,0 +1,24 @@
+class Solution {
+    func findContinuousSequence(_ target: Int) -> [[Int]] {
+        var l = 1, r = 2
+        var result = [[Int]]()
+        
+        while l < r {
+            let sum = (l + r) * (r - l + 1) / 2
+            if sum == target {
+                var sequence = [Int]()
+                for i in l...r {
+                    sequence.append(i)
+                }
+                result.append(sequence)
+                l += 1
+            } else if sum < target {
+                r += 1
+            } else {
+                l += 1
+            }
+        }
+        
+        return result
+    }
+}