feat: add solution 2 swift implementation to lcof2 problem: No.096 (doocs#3483)

Author: klever34

lcof2/剑指 Offer II 096. 字符串交织/README.md

@@ -685,6 +685,37 @@ public class Solution {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func isInterleave(_ s1: String, _ s2: String, _ s3: String) -> Bool {
+        let m = s1.count, n = s2.count
+        if m + n != s3.count {
+            return false
+        }
+        
+        let s1 = Array(s1), s2 = Array(s2), s3 = Array(s3)
+        var dp = Array(repeating: Array(repeating: false, count: n + 1), count: m + 1)
+        dp[0][0] = true
+        
+        for i in 0...m {
+            for j in 0...n {
+                let k = i + j - 1
+                if i > 0 && s1[i - 1] == s3[k] {
+                    dp[i][j] = dp[i][j] || dp[i - 1][j]
+                }
+                if j > 0 && s2[j - 1] == s3[k] {
+                    dp[i][j] = dp[i][j] || dp[i][j - 1]
+                }
+            }
+        }
+        
+        return dp[m][n]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 096. 字符串交织/Solution2.swift

@@ -0,0 +1,26 @@
+class Solution {
+    func isInterleave(_ s1: String, _ s2: String, _ s3: String) -> Bool {
+        let m = s1.count, n = s2.count
+        if m + n != s3.count {
+            return false
+        }
+        
+        let s1 = Array(s1), s2 = Array(s2), s3 = Array(s3)
+        var dp = Array(repeating: Array(repeating: false, count: n + 1), count: m + 1)
+        dp[0][0] = true
+        
+        for i in 0...m {
+            for j in 0...n {
+                let k = i + j - 1
+                if i > 0 && s1[i - 1] == s3[k] {
+                    dp[i][j] = dp[i][j] || dp[i - 1][j]
+                }
+                if j > 0 && s2[j - 1] == s3[k] {
+                    dp[i][j] = dp[i][j] || dp[i][j - 1]
+                }
+            }
+        }
+        
+        return dp[m][n]
+    }
+}