Merge (Algorithms 4/e)

Object
- edu.princeton.cs.algs4.Merge

```
public class Merge
extends Object
```
The Merge class provides static methods for sorting an array using a top-down, recursive version of mergesort.
This implementation takes Θ(n log n) time to sort any array of length n (assuming comparisons take constant time). It makes between ~ ½ n log₂ n and ~ 1 n log₂ n compares.
This sorting algorithm is stable. It uses Θ(n) extra memory (not including the input array).
For additional documentation, see Section 2.2 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne. For an optimized version, see MergeX.

Author:

Robert Sedgewick, Kevin Wayne

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static int[]`	`indexSort(Comparable[] a)`	Returns a permutation that gives the elements in the array in ascending order.
`static void`	`main(String[] args)`	Reads in a sequence of strings from standard input; mergesorts them; and prints them to standard output in ascending order.
`static void`	`sort(Comparable[] a)`	Rearranges the array in ascending order, using the natural order.

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - sort
```
public static void sort(Comparable[] a)
```
    Rearranges the array in ascending order, using the natural order.
    
    Parameters:
    
    a - the array to be sorted
  - indexSort
```
public static int[] indexSort(Comparable[] a)
```
    Returns a permutation that gives the elements in the array in ascending order.
    
    Parameters:
    
    a - the array
    
    Returns:
    
    a permutation p[] such that a[p[0]], a[p[1]], ..., a[p[n-1]] are in ascending order
  - main
```
public static void main(String[] args)
```
    Reads in a sequence of strings from standard input; mergesorts them; and prints them to standard output in ascending order.
    
    Parameters:
    
    args - the command-line arguments