A "list of arrays"? Really? Or an array of numbers? "can someone create an object for me" Not really, policy here, even more for homework, is to guide and help, not to code in place of the student...
"i have no idea where to start" In general, it is a good idea to search the forum, this kind of request have been already made. Also look at the tutorials and the examples. Useful stuff: arrays, for loops, fill(), rect().
That's not hard, think about the assignment, try to make something, show it here, we will guide you to improve it.
Try to take the problem from another side: make an array of numbers, filled by using a for loop. Then in draw(), loop over the array, and for each number, compute an offset (where to draw the rectangle) and a size based on the number. Then use rect() to draw this rectangle.
Easier? Not really. Looks quite good already. You can get rid of the biggest() function which doesn't seem to be used (it is incorrect, you should have result = z[j] in the loop). There are some steps that can be simplified, you can rely less on global variables, but otherwise, it works. Look at nfc() and similar for better alignment on the decimal point.