mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-01-11 02:58:13 +08:00
48 lines
2.2 KiB
HTML
48 lines
2.2 KiB
HTML
<p>You are given a <strong>0-indexed</strong> <code>m x n</code> integer matrix <code>grid</code>. Your initial position is at the <strong>top-left</strong> cell <code>(0, 0)</code>.</p>
|
|
|
|
<p>Starting from the cell <code>(i, j)</code>, you can move to one of the following cells:</p>
|
|
|
|
<ul>
|
|
<li>Cells <code>(i, k)</code> with <code>j < k <= grid[i][j] + j</code> (rightward movement), or</li>
|
|
<li>Cells <code>(k, j)</code> with <code>i < k <= grid[i][j] + i</code> (downward movement).</li>
|
|
</ul>
|
|
|
|
<p>Return <em>the minimum number of cells you need to visit to reach the <strong>bottom-right</strong> cell</em> <code>(m - 1, n - 1)</code>. If there is no valid path, return <code>-1</code>.</p>
|
|
|
|
<p> </p>
|
|
<p><strong class="example">Example 1:</strong></p>
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2023/01/25/ex1.png" style="width: 271px; height: 171px;" />
|
|
<pre>
|
|
<strong>Input:</strong> grid = [[3,4,2,1],[4,2,3,1],[2,1,0,0],[2,4,0,0]]
|
|
<strong>Output:</strong> 4
|
|
<strong>Explanation:</strong> The image above shows one of the paths that visits exactly 4 cells.
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 2:</strong></p>
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2023/01/25/ex2.png" style="width: 271px; height: 171px;" />
|
|
<pre>
|
|
<strong>Input:</strong> grid = [[3,4,2,1],[4,2,1,1],[2,1,1,0],[3,4,1,0]]
|
|
<strong>Output:</strong> 3
|
|
<strong>Explanation: </strong>The image above shows one of the paths that visits exactly 3 cells.
|
|
</pre>
|
|
|
|
<p><strong class="example">Example 3:</strong></p>
|
|
<img alt="" src="https://assets.leetcode.com/uploads/2023/01/26/ex3.png" style="width: 181px; height: 81px;" />
|
|
<pre>
|
|
<strong>Input:</strong> grid = [[2,1,0],[1,0,0]]
|
|
<strong>Output:</strong> -1
|
|
<strong>Explanation:</strong> It can be proven that no path exists.
|
|
</pre>
|
|
|
|
<p> </p>
|
|
<p><strong>Constraints:</strong></p>
|
|
|
|
<ul>
|
|
<li><code>m == grid.length</code></li>
|
|
<li><code>n == grid[i].length</code></li>
|
|
<li><code>1 <= m, n <= 10<sup>5</sup></code></li>
|
|
<li><code>1 <= m * n <= 10<sup>5</sup></code></li>
|
|
<li><code>0 <= grid[i][j] < m * n</code></li>
|
|
<li><code>grid[m - 1][n - 1] == 0</code></li>
|
|
</ul>
|