Max Points on a Line
<p>Given an array of <code>points</code> where <code>points[i] = [x<sub>i</sub>, y<sub>i</sub>]</code> represents a point on the <strong>X-Y</strong> plane, return <em>the maximum number of points that lie on the same straight line</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0100-0199/0149.Max%20Points%20on%20a%20Line/images/plane1.jpg" style="width: 300px; height: 294px;" />
<pre>
<strong>Input:</strong> points = [[1,1],[2,2],[3,3]]
<strong>Output:</strong> 3
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0100-0199/0149.Max%20Points%20on%20a%20Line/images/plane2.jpg" style="width: 300px; height: 294px;" />
<pre>
<strong>Input:</strong> points = [[1,1],[3,2],[5,3],[4,1],[2,3],[1,4]]
<strong>Output:</strong> 4
</pre>

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

<ul>
	<li><code>1 &lt;= points.length &lt;= 300</code></li>
	<li><code>points[i].length == 2</code></li>
	<li><code>-10<sup>4</sup> &lt;= x<sub>i</sub>, y<sub>i</sub> &lt;= 10<sup>4</sup></code></li>
	<li>All the <code>points</code> are <strong>unique</strong>.</li>
</ul>
Geometry; Array; Hash Table; Math
func maxPoints(points [][]int) int {
	n := len(points)
	ans := 1
	for i := 0; i < n; i++ {
		x1, y1 := points[i][0], points[i][1]
		for j := i + 1; j < n; j++ {
			x2, y2 := points[j][0], points[j][1]
			cnt := 2
			for k := j + 1; k < n; k++ {
				x3, y3 := points[k][0], points[k][1]
				a := (y2 - y1) * (x3 - x1)
				b := (y3 - y1) * (x2 - x1)
				if a == b {
					cnt++
				}
			}
			if ans < cnt {
				ans = cnt
			}
		}
	}
	return ans
}