feat: add swift implementation to lcof2 problem: No.093 (doocs#3479)

Author: klever34

lcof2/剑指 Offer II 093. 最长斐波那契数列/README.md

@@ -188,6 +188,35 @@ func lenLongestFibSubseq(arr []int) int {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func lenLongestFibSubseq(_ arr: [Int]) -> Int {
+        let n = arr.count
+        var mp = [Int: Int]()
+        for i in 0..<n {
+            mp[arr[i]] = i
+        }
+        
+        var dp = Array(repeating: Array(repeating: 2, count: n), count: n)
+        var ans = 0
+        
+        for i in 0..<n {
+            for j in 0..<i {
+                let delta = arr[i] - arr[j]
+                if let k = mp[delta], k < j {
+                    dp[j][i] = dp[k][j] + 1
+                    ans = max(ans, dp[j][i])
+                }
+            }
+        }
+        
+        return ans > 2 ? ans : 0
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 093. 最长斐波那契数列/Solution.swift

@@ -0,0 +1,24 @@
+class Solution {
+    func lenLongestFibSubseq(_ arr: [Int]) -> Int {
+        let n = arr.count
+        var mp = [Int: Int]()
+        for i in 0..<n {
+            mp[arr[i]] = i
+        }
+        
+        var dp = Array(repeating: Array(repeating: 2, count: n), count: n)
+        var ans = 0
+        
+        for i in 0..<n {
+            for j in 0..<i {
+                let delta = arr[i] - arr[j]
+                if let k = mp[delta], k < j {
+                    dp[j][i] = dp[k][j] + 1
+                    ans = max(ans, dp[j][i])
+                }
+            }
+        }
+        
+        return ans > 2 ? ans : 0
+    }
+}