fn main() {
    let result = square_of_sum(100) - sum_of_squares(100);
    println!("Result: {}", result);
}

fn square_of_sum(range: i64) -> i64 {
    (1..=range).sum::<i64>().pow(2)
}

fn sum_of_squares(range: i64) -> i64 {
    (1..=range).map(|n| n.pow(2)).sum()
}

#[cfg(test)]
mod tests {
    use crate::{square_of_sum, sum_of_squares};

    #[test]
    fn it_works() {
        let result = square_of_sum(10) - sum_of_squares(10);
        assert_eq!(result, 2640);
    }
}