Update 0417.太平洋大西洋水流问题.md

problems/0417.太平洋大西洋水流问题.md

@@ -562,7 +562,109 @@ function pacificAtlantic(heights) {
 }
 ```
 
+### go
 
+dfs:
+
+```go
+var DIRECTIONS = [4][2]int{{-1, 0}, {1, 0}, {0, -1}, {0, 1}}
+
+func pacificAtlantic(heights [][]int) [][]int {
+	res := make([][]int, 0)
+	pacific := make([][]bool, len(heights))
+	atlantic := make([][]bool, len(heights))
+	for i := 0; i < len(heights); i++ {
+		pacific[i] = make([]bool, len(heights[0]))
+		atlantic[i] = make([]bool, len(heights[0]))
+	}
+	// 列
+	for i := 0; i < len(heights); i++ {
+		dfs(heights, pacific, i, 0)
+		dfs(heights, atlantic, i, len(heights[0])-1)
+	}
+	// 行
+	for j := 0; j < len(heights[0]); j++ {
+		dfs(heights, pacific, 0, j)
+		dfs(heights, atlantic, len(heights)-1, j)
+	}
+
+	for i := 0; i < len(heights); i++ {
+		for j := 0; j < len(heights[0]); j++ {
+			if pacific[i][j] && atlantic[i][j] {
+				res = append(res, []int{i, j})
+			}
+		}
+	}
+
+	return res
+}
+
+func dfs(heights [][]int, visited [][]bool, i, j int) {
+	visited[i][j] = true
+	for _, d := range DIRECTIONS {
+		x, y := i+d[0], j+d[1]
+		if x < 0 || x >= len(heights) || y < 0 || y >= len(heights[0]) || heights[i][j] > heights[x][y] || visited[x][y] {
+			continue
+		}
+
+		dfs(heights, visited, x, y)
+	}
+}
+```
+
+bfs:
+
+```go
+var DIRECTIONS = [4][2]int{{-1, 0}, {1, 0}, {0, -1}, {0, 1}}
+
+func pacificAtlantic(heights [][]int) [][]int {
+	res := make([][]int, 0)
+	pacific := make([][]bool, len(heights))
+	atlantic := make([][]bool, len(heights))
+	for i := 0; i < len(heights); i++ {
+		pacific[i] = make([]bool, len(heights[0]))
+		atlantic[i] = make([]bool, len(heights[0]))
+	}
+	// 列
+	for i := 0; i < len(heights); i++ {
+		bfs(heights, pacific, i, 0)
+		bfs(heights, atlantic, i, len(heights[0])-1)
+	}
+	// 行
+	for j := 0; j < len(heights[0]); j++ {
+		bfs(heights, pacific, 0, j)
+		bfs(heights, atlantic, len(heights)-1, j)
+	}
+
+	for i := 0; i < len(heights); i++ {
+		for j := 0; j < len(heights[0]); j++ {
+			if pacific[i][j] && atlantic[i][j] {
+				res = append(res, []int{i, j})
+			}
+		}
+	}
+
+	return res
+}
+
+func bfs(heights [][]int, visited [][]bool, i, j int) {
+	queue := make([][]int, 0)
+	queue = append(queue, []int{i, j})
+	visited[i][j] = true
+	for len(queue) > 0 {
+		cur := queue[0]
+		queue = queue[1:]
+		for _, d := range DIRECTIONS {
+			x, y := cur[0]+d[0], cur[1]+d[1]
+			if x < 0 || x >= len(heights) || y < 0 || y >= len(heights[0]) || heights[cur[0]][cur[1]] > heights[x][y] || visited[x][y] {
+				continue
+			}
+			queue = append(queue, []int{x, y})
+			visited[x][y] = true
+		}
+	}
+}
+```
 
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">