- Examine and test the factorial functions
`fact(n)`where`n`is`int`,`Integer`,`long`,`float`, and`double`. For how large a value of`n`does`fact(n)`correctly and accurately compute the factorial in each case? (We will assume that "accurately" means that all digits of the factorial are correct.) Be careful: most students get this wrong. Did you get any indication (such as a runtime exception) if the value of the factorial was incorrect? - The file
`timing.java`contains some mystery functions`mickey`,`minnie`,`donald`,`goofy`,`pluto`,`gyro`, and`daffy`, and also a`BigInteger`version of`fact`. We want to analyze the performance of these functions experimentally.Use the

`Stopwatch`to time the functions:Stopwatch timer = new Stopwatch(); ... initialize arguments first timer.start(); ... code to be timed timer.stop(); System.out.println(timer);

For

`daffy`and`donald`, time the functions for values of`n`from`30`through`44`. Plot these times (if appropriate) on semi-log paper.For

`mickey`,`minnie`,`goofy`, and`pluto`, initialize by making an array of size`n`with`randomarr(n)`. The initialization of the array should not be inside the timing calls. Use values of`n`of`1000`,`2000`,`4000`... through`128000`.For

`gyro`, make an array using`randomarr(n)`and call`pluto`on it first. (`pluto`should not be included in the timing). Use values of`n`of`1000`,`2000`,`4000`... through`128000`.For

`fact(BigInteger n)`, test on values of`n`from`1000`through`64000`, doubling each time. You can make a`BigInteger`using code such as:BigInteger bign = BigInteger.valueOf((long) 1000);

A`BigInteger``bign`that is not too large can be converted to an`int`using`bign.intValue()`. There are operations`.add()`,`.subtract()`,`.multiply()`, and`.divide()`, each with a`BigInteger`argument.For each of the functions, plot the time taken vs.

`n`on log-log paper and estimate the big-O for the function. Note that the timer will not be accurate for very small times, e.g. less than a millisecond (0.001 second). If all the times of a function are too small, just report that the function is too fast to measure (and don't plot it). Do not include times that are too small in your plots, since the reported times are just noise.For

`mickey`,`minnie`,`goofy`, and`pluto`, also estimate the Big O of each function using the ratio of times as the input size is doubled. The time of the stopwatch in seconds can be obtained (as`double`) as`timer.time()`. For small values of the input size, the times will be noisy and the ratio will not be meaningful, so you may need to ignore the first few ratio values and concentrate on the ratios for larger inputs.