use crate::lcs::diff;

mod matrix;
mod lcs;

fn main() {
    let a = "abcd";
    let b = "abce";

    // diff(a, b);
    lcs(a, b);
}

fn lcs(a: &str, b: &str) {
    let n = a.len();
    let m = b.len();
    let max = (n + m) / 2;
    let mut v = vec![0usize; max * 2];

    for d in 0..max {
        let mut k = 0usize;
        while k <= d * 2 {
            let mut x = if k == 0 || k != d * 2 && v[k - 1] < v[k + 1] {
                v[k + 1]
            } else {
                v[k - 1] + 1
            };

            let mut y = if k < x {
                x - k
            } else {
                0
            };

            while x < n && y < m {
                let ac = a.chars().nth(x + 1).unwrap();
                let bc = b.chars().nth(y + 1).unwrap();

                if ac != bc {
                    break;
                }

                x = x + 1;
                y = y + 1;
            }

            v[k] = x;
            if x >= n && y >= m {
                println!("Length of a SES is D ({d})");
                dbg!(v);
                return;
            }

            k += 2;
        }
    }

    println!("Length of a SES is greater than MAX ({max})");
    dbg!(v);
}