Time: 113 ms (36.66%), Space: 14 MB (48.05%) - LeetHub

Author: chrispangg

0994-rotting-oranges/0994-rotting-oranges.py

@@ -0,0 +1,40 @@
+class Solution:
+    def orangesRotting(self, grid: List[List[int]]) -> int:
+        rows, cols = len(grid), len(grid[0])
+        q = collections.deque()
+        fresh, time = 0, 0
+        
+        for r in range(rows):
+            for c in range(cols):
+                if grid[r][c] == 1:
+                    fresh += 1
+                if grid[r][c] == 2:
+                    q.append((r, c))
+        
+        visited = set()
+        directions = [[1, 0],[-1, 0], [0, 1], [0, -1]]
+        while q and fresh > 0:
+            for i in range(len(q)):
+                row, col = q.popleft()
+
+                for dr, dc in directions:
+                    r, c = row + dr, col + dc
+                    if (r >= 0 and c >= 0 and 
+                        r < rows and c < cols and 
+                        grid[r][c] == 1 and
+                        (r, c) not in visited):
+                        
+                        grid[r][c] = 2
+                        visited.add((r, c))
+                        q.append((r, c))
+                        fresh -= 1
+            time += 1
+                
+
+        return time if fresh == 0 else -1
+        
+        
+        
+            
+        
+