mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-01-11 02:58:13 +08:00
37 lines
1.5 KiB
HTML
37 lines
1.5 KiB
HTML
|
<p>A robot is located at the top-left corner of a <code>m x n</code> grid (marked 'Start' in the diagram below).</p>
|
||
|
|
|
||
|
|
<p>The robot can only move either down or right at any point in time. The robot is trying to reach the bottom-right corner of the grid (marked 'Finish' in the diagram below).</p>
|
||
|
|
|
||
|
|
<p>Now consider if some obstacles are added to the grids. How many unique paths would there be?</p>
|
||
|
|
|
||
|
|
<p>An obstacle and space is marked as <code>1</code> and <code>0</code> respectively in the grid.</p>
|
||
|
|
|
||
|
|
<p> </p>
|
||
|
|
<p><strong>Example 1:</strong></p>
|
||
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2020/11/04/robot1.jpg" style="width: 242px; height: 242px;" />
|
||
|
|
<pre>
|
||
|
|
<strong>Input:</strong> obstacleGrid = [[0,0,0],[0,1,0],[0,0,0]]
|
||
|
|
<strong>Output:</strong> 2
|
||
|
|
<strong>Explanation:</strong> There is one obstacle in the middle of the 3x3 grid above.
|
||
|
|
There are two ways to reach the bottom-right corner:
|
||
|
|
1. Right -> Right -> Down -> Down
|
||
|
|
2. Down -> Down -> Right -> Right
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p><strong>Example 2:</strong></p>
|
||
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2020/11/04/robot2.jpg" style="width: 162px; height: 162px;" />
|
||
|
|
<pre>
|
||
|
|
<strong>Input:</strong> obstacleGrid = [[0,1],[0,0]]
|
||
|
|
<strong>Output:</strong> 1
|
||
|
|
</pre>
|
||
|
|
|
||
|
|
<p> </p>
|
||
|
|
<p><strong>Constraints:</strong></p>
|
||
|
|
|
||
|
|
<ul>
|
||
|
|
<li><code>m == obstacleGrid.length</code></li>
|
||
|
|
<li><code>n == obstacleGrid[i].length</code></li>
|
||
|
|
<li><code>1 <= m, n <= 100</code></li>
|
||
|
|
<li><code>obstacleGrid[i][j]</code> is <code>0</code> or <code>1</code>.</li>
|
||
|
|
</ul>
|