pub fn square_of_sum(n: u32) -> u32 { (1..=n).fold(0, |a,b| a+b).pow(2) } pub fn sum_of_squares(n: u32) -> u32 { (1..=n).fold(0, |a,b| a+b.pow(2)) } pub fn difference(n: u32) -> u32 { square_of_sum(n) - sum_of_squares(n) }