Create 0417-pacific-atlantic-water-flow.go

Accepted submission: _https://leetcode.com/submissions/detail/870855223/_

go/0417-pacific-atlantic-water-flow.go

@@ -0,0 +1,42 @@
+func pacificAtlantic(heights [][]int) [][]int {
+ ROWS, COLS := len(heights), len(heights[0])
+ pac, atl := make(map[int]bool), make(map[int] bool)
+
+ var dfs func(int, int, map[int]bool, int)
+ dfs = func(r, c int, visit map[int]bool, prevHeight int) {
+ if (
+ visit[r*COLS + c] ||
+ r < 0 ||
+ c < 0 ||
+ r == ROWS ||
+ c == COLS ||
+ heights[r][c] < prevHeight) {
+ return;
+ }
+ visit[r*COLS + c] = true
+ dfs(r + 1, c, visit, heights[r][c])
+ dfs(r - 1, c, visit, heights[r][c])
+ dfs(r, c + 1, visit, heights[r][c])
+ dfs(r, c - 1, visit, heights[r][c])
+ }
+
+ for c := 0; c < COLS; c++ {
+ dfs(0, c, pac, heights[0][c])
+ dfs(ROWS - 1, c, atl, heights[ROWS - 1][c])
+ }
+
+ for r := 0; r < ROWS; r++ {
+ dfs(r, 0, pac, heights[r][0])
+ dfs(r, COLS - 1, atl, heights[r][COLS - 1])
+ }
+
+ res := make([][]int, 0)
+ for r := 0; r < ROWS; r++ {
+ for c := 0; c < COLS; c++ {
+ if pac[r*COLS + c] && atl[r*COLS + c] {
+ res = append(res, []int{r, c})
+ }
+ }
+ }
+ return res
+}