feat: add swift implementation to lcof problem: No.62 (#2954)

lcof/面试题62. 圆圈中最后剩下的数字/README.md

@@ -161,6 +161,24 @@ public class Solution {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func lastRemaining(_ n: Int, _ m: Int) -> Int {
+        return f(n, m)
+    }
+
+    private func f(_ n: Int, _ m: Int) -> Int {
+        if n == 1 {
+            return 0
+        }
+        let x = f(n - 1, m)
+        return (m + x) % n
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof/面试题62. 圆圈中最后剩下的数字/Solution.swift

@@ -0,0 +1,13 @@
+class Solution {
+    func lastRemaining(_ n: Int, _ m: Int) -> Int {
+        return f(n, m)
+    }
+    
+    private func f(_ n: Int, _ m: Int) -> Int {
+        if n == 1 {
+            return 0
+        }
+        let x = f(n - 1, m)
+        return (m + x) % n
+    }
+}