cash-register.rs

use std::io::{BufReader,BufRead};
use std::fs::File; // File::open
use std::env; // argv_os

fn main() {
	let fd = BufReader::new(File::open(env::args_os().nth(1).unwrap()).unwrap());
	let arr: Vec<Vec<f64>> = fd.lines()
		.map(|l| l.unwrap().split(';')
			.map(|number| number.parse().unwrap())
			.collect())
		.collect();
	for x in arr {
		if x[0] > x[1] {
			println!("ERROR");
		} else if x[0] == x[1] {
			println!("ZERO");
		} else {
			let mut nx = x[1] - x[0];
			let mut comma = false;
			'inf: loop {
				if nx <= 0.001 {
					break;
				}
				if comma {
					print!(",");
				}
				// giant denomination if-else
				if nx >= 100.0 {
					nx -= 100.0;
					print!("ONE HUNDRED");
				} else if nx >= 50.0 {
					nx -= 50.0;
					print!("FIFTY");
				} else if nx >= 20.0 {
					nx -= 20.0;
					print!("TWENTY");
				} else if nx >= 10.0 {
					nx -= 10.0;
					print!("TEN");
				} else if nx >= 5.0 {
					nx -= 5.0;
					print!("FIVE");
				} else if nx >= 2.0 {
					nx -= 2.0;
					print!("TWO");
				} else if nx >= 1.0 {
					nx -= 1.0;
					print!("ONE");
				} else if nx >= 0.5 {
					nx -= 0.5;
					print!("HALF DOLLAR");
				} else if nx >= 0.25 {
					nx -= 0.25;
					print!("QUARTER");
				} else if nx >= 0.10 {
					nx -= 0.10;
					print!("DIME");
				} else if nx >= 0.05 {
					nx -= 0.05;
					print!("NICKEL");
				} else if nx >= 0.01 {
					nx -= 0.01;
					print!("PENNY");
				}
				comma = true; // from now on print a comma
			}
			println!(""); // new line
		}
	}
}