Feat : Number of Islands

Author: printjin-gmailcom

number-of-islands/printjin-gmailcom.py

@@ -0,0 +1,24 @@
+class Solution:
+    def numIslands(self, grid):
+        if not grid:
+            return 0
+        
+        rows, cols = len(grid), len(grid[0])
+        count = 0
+
+        def dfs(r, c):
+            if r < 0 or c < 0 or r >= rows or c >= cols or grid[r][c] == "0":
+                return
+            grid[r][c] = "0"
+            dfs(r+1, c)
+            dfs(r-1, c)
+            dfs(r, c+1)
+            dfs(r, c-1)
+
+        for r in range(rows):
+            for c in range(cols):
+                if grid[r][c] == "1":
+                    dfs(r, c)
+                    count += 1
+
+        return count