feat: add swift implementation to lcp problem: No.07 (#3742)

Author: klever34

lcp/LCP 07. 传递信息/README.md

@@ -155,6 +155,25 @@ function numWays(n: number, relation: number[][], k: number): number {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func numWays(_ n: Int, _ relation: [[Int]], _ k: Int) -> Int {
+        var f = Array(repeating: Array(repeating: 0, count: n), count: k + 1)
+        f[0][0] = 1
+        
+        for i in 1...k {
+            for r in relation {
+                let a = r[0], b = r[1]
+                f[i][b] += f[i - 1][a]
+            }
+        }
+        return f[k][n - 1]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcp/LCP 07. 传递信息/Solution.swift

@@ -0,0 +1,14 @@
+class Solution {
+    func numWays(_ n: Int, _ relation: [[Int]], _ k: Int) -> Int {
+        var f = Array(repeating: Array(repeating: 0, count: n), count: k + 1)
+        f[0][0] = 1
+        
+        for i in 1...k {
+            for r in relation {
+                let a = r[0], b = r[1]
+                f[i][b] += f[i - 1][a]
+            }
+        }
+        return f[k][n - 1]
+    }
+}