Create 994-Rotting-Oranges.py

Author: neetcode-gh

994-Rotting-Oranges.py

@@ -0,0 +1,31 @@
+class Solution:
+    def orangesRotting(self, grid: List[List[int]]) -> int:
+        q = collections.deque()
+        fresh = 0
+        time = 0
+        
+        for r in range(len(grid)):
+            for c in range(len(grid[0])):
+                if grid[r][c] == 1:
+                    fresh += 1
+                if grid[r][c] == 2:
+                    q.append((r, c))
+                    
+        directions = [[0, 1], [0, -1], [1, 0], [-1, 0]]
+        while fresh > 0 and q:
+            length = len(q)
+            for i in range(length):
+                r, c = q.popleft()
+                
+                for dr, dc in directions:
+                    row, col = r + dr, c + dc
+                    # if in bounds and nonrotten, make rotten
+                    # and add to q
+                    if row in range(len(grid)) and \
+                        col in range(len(grid[0])) and \
+                        grid[row][col] == 1:
+                        grid[row][col] = 2
+                        q.append((row, col))
+                        fresh -= 1
+            time += 1
+        return time if fresh == 0 else -1