GrahamScan (Algorithms 4/e)

Object
- edu.princeton.cs.algs4.GrahamScan

```
public class GrahamScan
extends Object
```
The GrahamScan data type provides methods for computing the convex hull of a set of n points in the plane.
The implementation uses the Graham-Scan convex hull algorithm. It runs in O(n log n) time in the worst case and uses O(n) extra memory.
For additional documentation, see Section 9.9 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.

Author:

Robert Sedgewick, Kevin Wayne

Constructor Summary

Constructors
Constructor and Description

GrahamScan(Point2D[] points)
Computes the convex hull of the specified array of points.

Method Summary

Methods
Modifier and Type	Method and Description
`Iterable<Point2D>`	`hull()` Returns the extreme points on the convex hull in counterclockwise order.
`static void`	`main(String[] args)` Unit tests the `GrahamScan` data type.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - GrahamScan
```
public GrahamScan(Point2D[] points)
```
    Computes the convex hull of the specified array of points.
    
    Parameters:
    points - the array of points
    
    Throws:
    
    IllegalArgumentException - if points is null
    
    IllegalArgumentException - if any entry in points[] is null
    
    IllegalArgumentException - if points.length is 0
- Method Detail
  - hull
```
public Iterable<Point2D> hull()
```
    Returns the extreme points on the convex hull in counterclockwise order.
    
    Returns:
    the extreme points on the convex hull in counterclockwise order
  - main
```
public static void main(String[] args)
```
    Unit tests the GrahamScan data type. Reads in an integer n and n points (specified by their x- and y-coordinates) from standard input; computes their convex hull; and prints out the points on the convex hull to standard output.
    
    Parameters:
    args - the command-line arguments