feat: add swift implementation to lcof2 problem: No.105

lcof2/剑指 Offer II 105. 岛屿的最大面积/README.md

@@ -250,6 +250,50 @@ impl Solution {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    private var m = 0
+    private var n = 0
+    private var grid: [[Int]] = []
+
+    func maxAreaOfIsland(_ grid: [[Int]]) -> Int {
+        self.m = grid.count
+        self.n = grid[0].count
+        self.grid = grid
+        var maxArea = 0
+
+        for i in 0..<m {
+            for j in 0..<n {
+                maxArea = max(maxArea, dfs(i, j))
+            }
+        }
+
+        return maxArea
+    }
+
+    private func dfs(_ i: Int, _ j: Int) -> Int {
+        if grid[i][j] == 0 {
+            return 0
+        }
+
+        var area = 1
+        grid[i][j] = 0
+        let dirs = [-1, 0, 1, 0, -1]
+
+        for k in 0..<4 {
+            let x = i + dirs[k], y = j + dirs[k + 1]
+            if x >= 0 && x < m && y >= 0 && y < n {
+                area += dfs(x, y)
+            }
+        }
+
+        return area
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 105. 岛屿的最大面积/Solution.swift

@@ -0,0 +1,39 @@
+class Solution {
+    private var m = 0
+    private var n = 0
+    private var grid: [[Int]] = []
+
+    func maxAreaOfIsland(_ grid: [[Int]]) -> Int {
+        self.m = grid.count
+        self.n = grid[0].count
+        self.grid = grid
+        var maxArea = 0
+
+        for i in 0..<m {
+            for j in 0..<n {
+                maxArea = max(maxArea, dfs(i, j))
+            }
+        }
+
+        return maxArea
+    }
+
+    private func dfs(_ i: Int, _ j: Int) -> Int {
+        if grid[i][j] == 0 {
+            return 0
+        }
+
+        var area = 1
+        grid[i][j] = 0
+        let dirs = [-1, 0, 1, 0, -1]
+
+        for k in 0..<4 {
+            let x = i + dirs[k], y = j + dirs[k + 1]
+            if x >= 0 && x < m && y >= 0 && y < n {
+                area += dfs(x, y)
+            }
+        }
+
+        return area
+    }
+}