leetcode.com 417. Pacific Atlantic Water Flow

문제 링크: https://leetcode.com/problems/pacific-atlantic-water-flow/description/

Author: skysign

leetcode.com 417. Pacific Atlantic Water Flow/main.py

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+from typing import List
+
+
+class Solution:
+    def pacificAtlantic(self, heights: List[List[int]]) -> List[List[int]]:
+        MAX_ROW = len(heights)
+        MAX_COL = len(heights[0])
+        pacific: List[List] = [[False for _ in range(MAX_COL)] for _ in range(MAX_ROW)]
+        atlantic: List[List] = [[False for _ in range(MAX_COL)] for _ in range(MAX_ROW)]
+
+        def dfs(visited: List[List], prev_height, r, c):
+            if 0 <= r < MAX_ROW \
+                    and 0 <= c < MAX_COL \
+                    and visited[r][c] == False \
+                    and prev_height <= heights[r][c]:
+                visited[r][c] = True
+
+                dfs(visited, heights[r][c], r - 1, c)
+                dfs(visited, heights[r][c], r, c + 1)
+                dfs(visited, heights[r][c], r + 1, c)
+                dfs(visited, heights[r][c], r, c - 1)
+
+        for r in range(0, MAX_ROW):
+            dfs(pacific, 0, r, 0)
+            dfs(atlantic, 0, r, MAX_COL - 1)
+
+        for c in range(0, MAX_COL):
+            dfs(pacific, 0, 0, c)
+            dfs(atlantic, 0, MAX_ROW - 1, c)
+
+        answer: List[List] = []
+
+        for r in range(0, MAX_ROW):
+            for c in range(0, MAX_COL):
+                if pacific[r][c] and atlantic[r][c]:
+                    answer.append([r, c])
+
+        return answer

leetcode.com 417. Pacific Atlantic Water Flow/test_main.py

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+from unittest import TestCase
+from main import Solution
+
+class TestSolution(TestCase):
+    def test1_pacific_atlantic(self):
+        sol = Solution()
+        self.assertEqual([[0,4],[1,3],[1,4],[2,2],[3,0],[3,1],[4,0]],\
+                         sol.pacificAtlantic([[1,2,2,3,5],[3,2,3,4,4],[2,4,5,3,1],[6,7,1,4,5],[5,1,1,2,4]]))
+
+    def test2_pacific_atlantic(self):
+        sol = Solution()
+        self.assertEqual([[0,0]], sol.pacificAtlantic([[1]]))