feat: add swift implementation to lcof2 problem: No.098 (doocs#3503)

Author: klever34

lcof2/剑指 Offer II 098. 路径的数目/README.md

@@ -247,6 +247,30 @@ var uniquePaths = function (m, n) {
 };
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func uniquePaths(_ m: Int, _ n: Int) -> Int {
+        var dp = Array(repeating: Array(repeating: 0, count: n), count: m)
+        dp[0][0] = 1
+        
+        for i in 0..<m {
+            for j in 0..<n {
+                if i > 0 {
+                    dp[i][j] += dp[i - 1][j]
+                }
+                if j > 0 {
+                    dp[i][j] += dp[i][j - 1]
+                }
+            }
+        }
+        
+        return dp[m - 1][n - 1]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 098. 路径的数目/Solution.swift

@@ -0,0 +1,19 @@
+class Solution {
+    func uniquePaths(_ m: Int, _ n: Int) -> Int {
+        var dp = Array(repeating: Array(repeating: 0, count: n), count: m)
+        dp[0][0] = 1
+        
+        for i in 0..<m {
+            for j in 0..<n {
+                if i > 0 {
+                    dp[i][j] += dp[i - 1][j]
+                }
+                if j > 0 {
+                    dp[i][j] += dp[i][j - 1]
+                }
+            }
+        }
+        
+        return dp[m - 1][n - 1]
+    }
+}