feat: add swift implementation to lcof2 problem: No.008 (#2978)

Author: klever34

lcof2/剑指 Offer II 008. 和大于等于 target 的最短子数组/README.md

@@ -176,6 +176,30 @@ function minSubArrayLen(target: number, nums: number[]): number {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func minSubArrayLen(_ target: Int, _ nums: [Int]) -> Int {
+        let inf = Int.max
+        var ans = inf
+        var sum = 0
+        var i = 0
+        
+        for j in 0..<nums.count {
+            sum += nums[j]
+            while sum >= target {
+                ans = min(ans, j - i + 1)
+                sum -= nums[i]
+                i += 1
+            }
+        }
+        
+        return ans == inf ? 0 : ans
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 008. 和大于等于 target 的最短子数组/Solution.swift

@@ -0,0 +1,19 @@
+class Solution {
+    func minSubArrayLen(_ target: Int, _ nums: [Int]) -> Int {
+        let inf = Int.max
+        var ans = inf
+        var sum = 0
+        var i = 0
+        
+        for j in 0..<nums.count {
+            sum += nums[j]
+            while sum >= target {
+                ans = min(ans, j - i + 1)
+                sum -= nums[i]
+                i += 1
+            }
+        }
+        
+        return ans == inf ? 0 : ans
+    }
+}