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https://github.com/lucas-erkana/codingchallenege-pacific-atlantic-water-flow
Given an m x n island with heights, determine the cells where rainwater can flow to both the Pacific and Atlantic oceans. Water can flow north, south, east, or west if neighboring cells are lower/equal. Output a 2D list of grid coordinates representing the cells.
https://github.com/lucas-erkana/codingchallenege-pacific-atlantic-water-flow
Last synced: 5 days ago
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Given an m x n island with heights, determine the cells where rainwater can flow to both the Pacific and Atlantic oceans. Water can flow north, south, east, or west if neighboring cells are lower/equal. Output a 2D list of grid coordinates representing the cells.
- Host: GitHub
- URL: https://github.com/lucas-erkana/codingchallenege-pacific-atlantic-water-flow
- Owner: Lucas-Erkana
- Created: 2023-11-01T07:35:56.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2023-11-01T08:10:26.000Z (about 1 year ago)
- Last Synced: 2024-10-12T09:49:16.021Z (about 1 month ago)
- Language: JavaScript
- Size: 15.6 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# Pacific Atlantic Water Flow
There is an `m x n` rectangular island that borders both the Pacific Ocean and Atlantic Ocean. The Pacific Ocean touches the island's left and top edges, and the Atlantic Ocean touches the island's right and bottom edges.
The island is partitioned into a grid of square cells. You are given an `m x n` integer matrix `heights` where `heights[r][c]` represents the height above sea level of the cell at coordinate `(r, c)`.
The island receives a lot of rain, and the rainwater can flow to neighboring cells directly north, south, east, and west if the neighboring cell's height is less than or equal to the current cell's height. Water can flow from any cell adjacent to an ocean into the ocean.
Return a 2D list of grid coordinates `result` where `result[i] = [ri, ci]` denotes that rainwater can flow from cell `(ri, ci)` to both the Pacific and Atlantic oceans.
## Example 1:
**Input:**
```
heights = [[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]]
```
**Output:**
```
[[0,4],[1,3],[1,4],[2,2],[3,0],[3,1],[4,0]]
```
**Explanation:**
The following cells can flow to the Pacific and Atlantic oceans:
- [0,4]: [0,4] -> Pacific Ocean
[0,4] -> Atlantic Ocean
- [1,3]: [1,3] -> [0,3] -> Pacific Ocean
[1,3] -> [1,4] -> Atlantic Ocean
- [1,4]: [1,4] -> [1,3] -> [0,3] -> Pacific Ocean
[1,4] -> Atlantic Ocean
- [2,2]: [2,2] -> [1,2] -> [0,2] -> Pacific Ocean
[2,2] -> [2,3] -> [2,4] -> Atlantic Ocean
- [3,0]: [3,0] -> Pacific Ocean
[3,0] -> [4,0] -> Atlantic Ocean
- [3,1]: [3,1] -> [3,0] -> Pacific Ocean
[3,1] -> [4,1] -> Atlantic Ocean
- [4,0]: [4,0] -> Pacific Ocean
[4,0] -> Atlantic Ocean
Note that there are other possible paths for these cells to flow to the Pacific and Atlantic oceans.
## Example 2
**Input:**
```
heights = [[1]]
```
**Output:**
```
[[0,0]]
```
**Explanation:**
The water can flow from the only cell to the Pacific and Atlantic oceans.
## Constraints
- `m == heights.length`
- `n == heights[r].length`
- `1 <= m, n <= 200`
- `0 <= heights[r][c] <= 105`