day5_part2.jakt

/// Expect:
/// - output: "6188\n"

import reader

function previous_char(chars: &[u8], current: usize) -> usize {
    if current > 0 {
        let previous = current - 1
        for i in previous..0 {
            if chars[i] != 0 {
                return i
            }
        }
    }    

    return 0
}

function next_char(chars: &[u8], current: usize) -> usize {
    let next = current + 1
    if next < chars.size() {
        for i in next..chars.size() {
            if chars[i] != 0 {
                return i
            }
        }
    }

    return 0
}

function count_chars(chars: &[u8]) -> i32 {
    mut count = 0i32
    for char_ in chars.iterator() {
        if char_ != 0 {
            count++
        }
    }

    return count
}

function remove_char(chars: [u8], char_: u8) throws -> [u8] {
    mut chars_removed = chars

    for i in 0..chars.size() {
        if chars[i] == char_ or chars[i] == char_ + 32 {
            chars_removed[i] = 0
        }
    }

    return chars_removed
}

function main() {
    mut chars_base = reader::chars(day: 5)

    mut start = 0uz
    mut ended = false

    mut lowest_count = 100000i32

    for z in 65..91 {
        mut chars = remove_char(chars: chars_base[..].to_array(), char_: z as! u8)

        loop {
            mut i = 0uz
            while i < chars.size() {
                let char_ = chars[i]
                let next = next_char(&chars, current: i)
                if next != 0 {
                    if (char_ > chars[next] and char_ - chars[next] == 32) or
                        (chars[next] > char_ and chars[next] - char_ == 32) {
                        chars[i] = 0
                        chars[next] = 0

                        i = previous_char(&chars, current: i)
                    } else {
                        i = next
                    }
                } else {
                    ended = true
                    break
                }
            }

            if ended {
                break
            }
        }

        let count = count_chars(&chars)
        if count < lowest_count {
            lowest_count = count
        }
    }
    
    println("{}", lowest_count)
}