Merge pull request #1038 from Mark-777-0/patch-1

Adding BFS For Convenience

Author: Ahmad-A0

python/200-Number-of-Islands.py

@@ -27,3 +27,40 @@ def dfs(r, c):
                     islands += 1
                     dfs(r, c)
         return islands
+
+
+# BFS Version From Video
+class SolutionBFS:
+    def numIslands(self, grid: List[List[str]]) -> int:
+        if not grid:
+            return 0
+
+        rows, cols = len(grid), len(grid[0])
+        visited=set()
+        islands=0
+
+         def bfs(r,c):
+             q = deque()
+             visited.add((r,c))
+             q.append((r,c))
+           
+             while q:
+                 row,col = q.popleft()
+                 directions= [[1,0],[-1,0],[0,1],[0,-1]]
+               
+                 for dr,dc in directions:
+                     r,c = row + dr, col + dc
+                     if (r) in range(rows) and (c) in range(cols) and grid[r][c] == '1' and (r ,c) not in visited:
+                       
+                         q.append((r , c ))
+                         visited.add((r, c ))
+
+         for r in range(rows):
+             for c in range(cols):
+               
+                 if grid[r][c] == "1" and (r,c) not in visited:
+                     bfs(r,c)
+                     islands +=1 
+
+         return islands
+