{ "data": { "question": { "questionId": "2038", "questionFrontendId": "1926", "boundTopicId": null, "title": "Nearest Exit from Entrance in Maze", "titleSlug": "nearest-exit-from-entrance-in-maze", "content": "
You are given an m x n
matrix maze
(0-indexed) with empty cells (represented as '.'
) and walls (represented as '+'
). You are also given the entrance
of the maze, where entrance = [entrancerow, entrancecol]
denotes the row and column of the cell you are initially standing at.
In one step, you can move one cell up, down, left, or right. You cannot step into a cell with a wall, and you cannot step outside the maze. Your goal is to find the nearest exit from the entrance
. An exit is defined as an empty cell that is at the border of the maze
. The entrance
does not count as an exit.
Return the number of steps in the shortest path from the entrance
to the nearest exit, or -1
if no such path exists.
\n
Example 1:
\n\n\nInput: maze = [["+","+",".","+"],[".",".",".","+"],["+","+","+","."]], entrance = [1,2]\nOutput: 1\nExplanation: There are 3 exits in this maze at [1,0], [0,2], and [2,3].\nInitially, you are at the entrance cell [1,2].\n- You can reach [1,0] by moving 2 steps left.\n- You can reach [0,2] by moving 1 step up.\nIt is impossible to reach [2,3] from the entrance.\nThus, the nearest exit is [0,2], which is 1 step away.\n\n\n
Example 2:
\n\n\nInput: maze = [["+","+","+"],[".",".","."],["+","+","+"]], entrance = [1,0]\nOutput: 2\nExplanation: There is 1 exit in this maze at [1,2].\n[1,0] does not count as an exit since it is the entrance cell.\nInitially, you are at the entrance cell [1,0].\n- You can reach [1,2] by moving 2 steps right.\nThus, the nearest exit is [1,2], which is 2 steps away.\n\n\n
Example 3:
\n\n\nInput: maze = [[".","+"]], entrance = [0,0]\nOutput: -1\nExplanation: There are no exits in this maze.\n\n\n
\n
Constraints:
\n\nmaze.length == m
maze[i].length == n
1 <= m, n <= 100
maze[i][j]
is either '.'
or '+'
.entrance.length == 2
0 <= entrancerow < m
0 <= entrancecol < n
entrance
will always be an empty cell.Compiled with clang 11
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Most standard library headers are already included automatically for your convenience.
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