#778
Swim in Rising Water
expert · 1035 · lc hard +32 · verified · 67.6% accepted · 4,566 likes · top 74%
Description
You are given an n x n elevation grid where grid[i][j] is the height of cell (i, j). Water rises over time: at time t any cell with elevation <= t is accessible. You can swim between 4-directionally adjacent cells instantaneously as long as both cells' elevations are <= t.
Starting at (0, 0), return the minimum time t at which you can reach (n-1, n-1).
Example 1:
Input: grid = [[0,2],[1,3]]
Output: 3
Explanation:
At time 0, you are in grid location (0, 0).
You cannot go anywhere else because 4-directionally adjacent neighbors have a higher elevation than t = 0.
You cannot reach point (1, 1) until time 3.
When the depth of water is 3, we can swim anywhere inside the grid.
Example 2:
Input: grid = [[0,1,2,3,4],[24,23,22,21,5],[12,13,14,15,16],[11,17,18,19,20],[10,9,8,7,6]]
Output: 16
Explanation: The final route is shown.
We need to wait until time 16 so that (0, 0) and (4, 4) are connected.
Code
1
2
3