Solution Number of islands

Author: doitduri

number-of-islands/doitduri.swift

@@ -0,0 +1,34 @@
+class Solution {
+    func numIslands(_ grid: [[Character]]) -> Int {
+        guard !grid.isEmpty else { return 0 }
+        
+        let rows = grid.count
+        let colums = grid[0].count
+        var visited = grid
+        var islandCount = 0
+        
+        func dfs(_ row: Int, _ col: Int) {
+            guard row >= 0 && row < rows && col >= 0 && col < colums && visited[row][col] == "1" else {
+                return
+            }
+            
+            visited[row][col] = "0"
+            
+            dfs(row - 1, col)
+            dfs(row + 1, col)
+            dfs(row, col - 1)
+            dfs(row, col + 1)
+        }
+        
+        for row in 0..<rows {
+            for col in 0..<colums {
+                if visited[row][col] == "1" {
+                    islandCount += 1
+                    dfs(row, col)
+                }
+            }
+        }
+        
+        return islandCount
+    }
+}