use std::f64;
fn main() {
println!("{}", f64::floor(50.0));
println!("{}", f64::floor(50.1));
println!("{}", f64::floor(5.4));
println!("{}", f64::floor(5.5));
println!("{}", f64::floor(5.6));
println!("{}", f64::floor(-10.0));
println!("{}", f64::floor(-13.4));
println!("{}", f64::floor(-13.5));
println!("{}", f64::floor(-13.6));
println!("{}", f64::floor(0.0));
}
/*
run:
50
50
5
5
5
-10
-14
-14
-14
0
*/