StopwatchCPU (Algorithms 4/e)

Object
- edu.princeton.cs.algs4.StopwatchCPU

```
public class StopwatchCPU
extends Object
```
The StopwatchCPU data type is for measuring the CPU time used during a programming task. See Stopwatch for a version that measures wall-clock time (the real time that elapses).

Author:

Josh Hug, Robert Sedgewick, Kevin Wayne

Constructor Summary

Constructors
Constructor and Description

StopwatchCPU()
Initializes a new stopwatch.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`double`	`elapsedTime()` Returns the elapsed CPU time (in seconds) since the stopwatch was created.
`static void`	`main(String[] args)` Unit tests the `StopwatchCPU` data type.

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

- Constructor Detail
  - StopwatchCPU
```
public StopwatchCPU()
```
    Initializes a new stopwatch.
- Method Detail
  - elapsedTime
```
public double elapsedTime()
```
    Returns the elapsed CPU time (in seconds) since the stopwatch was created.
    
    Returns:
    
    elapsed CPU time (in seconds) since the stopwatch was created
  - main
```
public static void main(String[] args)
```
    Unit tests the StopwatchCPU data type. Takes a command-line argument n and computes the sum of the square roots of the first n positive integers, first using Math.sqrt(), then using Math.pow(). It prints to standard output the sum and the amount of time to compute the sum. Note that the discrete sum can be approximated by an integral - the sum should be approximately 2/3 * (n^(3/2) - 1).
    
    Parameters:
    
    args - the command-line arguments