rendezvous with cassidoo challenge: 24.02.26

remove_digit.rs

pub fn remove_digit(n: i32, digit: i32) -> i32 {
    let digit_char = char::from_digit(digit as u32, 10).unwrap();
    let n_str = n.to_string();
    let mut max_num = 0;

    for (i, c) in n_str.char_indices() {
        if c == digit_char {
            let new_num_str = [&n_str[..i], &n_str[i + 1..]].concat();
            let new_num = new_num_str.parse::<i32>().unwrap();

            if new_num > max_num {
                max_num = new_num;
            }
        }
    }

    if max_num == 0 {
        return n;
    }

    max_num
}

#[test]
fn remove_digit_test() {
    assert_eq!(3415926, remove_digit(31415926, 1));
    assert_eq!(231, remove_digit(1231, 1));
}