leetcode-problemset/leetcode/problem/self-crossing.html

<p>You are given an array of integers <code>distance</code>.</p>

<p>You start at the point <code>(0, 0)</code> on an <strong>X-Y plane,</strong> and you move <code>distance[0]</code> meters to the north, then <code>distance[1]</code> meters to the west, <code>distance[2]</code> meters to the south, <code>distance[3]</code> meters to the east, and so on. In other words, after each move, your direction changes counter-clockwise.</p>

<p>Return <code>true</code> <em>if your path crosses itself or </em><code>false</code><em> if it does not</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/12/21/11.jpg" style="width: 400px; height: 413px;" />
<pre>
<strong>Input:</strong> distance = [2,1,1,2]
<strong>Output:</strong> true
<strong>Explanation:</strong> The path crosses itself at the point (0, 1).
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/12/21/22.jpg" style="width: 400px; height: 413px;" />
<pre>
<strong>Input:</strong> distance = [1,2,3,4]
<strong>Output:</strong> false
<strong>Explanation:</strong> The path does not cross itself at any point.
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2022/12/21/33.jpg" style="width: 400px; height: 413px;" />
<pre>
<strong>Input:</strong> distance = [1,1,1,2,1]
<strong>Output:</strong> true
<strong>Explanation:</strong> The path crosses itself at the point (0, 0).
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;=&nbsp;distance.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;=&nbsp;distance[i] &lt;= 10<sup>5</sup></code></li>
</ul>