use std::collections::BTreeMap;
use std::ops::Bound::Included;

fn main () {
    test();
}

fn test() {
    let mut bt: BTreeMap<u128, u128> = BTreeMap::new();
    let mut a: u128 = 0;
    let div: u128 = 8;
    for x in 0..100_u128 {
        for y in 0..100_u128 {
            let zey = zeeify(x*div, y*div);
            a += 1;
            bt.insert(zey, a);
        }
    }
    let test = 400;
    println!("{:?}", zee_neighbors(test, 8));
    let n = zee_neighbors(400, 8);
    // [x: 40 y: 40] -> [x: 48, y: 48]
    let xs = 46;
    let ys = 46;
    for r in 0..div {
        let yss = (ys-div/2) + r;
        let xss = (xs-div/2);
        let minzee = zeeify(xss, yss);
        let maxzee = zeeify(xss+div, yss);
        for v in bt.range( (Included(minzee), Included(maxzee)) ) {
            println!("{:?}", v);
        }
    }

}

fn abs_u128(a: u128, b: u128) -> u128 {
    if a > b {a - b} else { b-a }
}

fn zee_neighbors(zee: u128, div: u128) -> [u128; 4] {
    let a: u128 = 0b10101010101010101010101010101010;
    let b: u128 = 0b01010101010101010101010101010101;
    let t: u128 = ((zee & a) - div & a) | (zee & b);
    let b: u128 = ((zee & b) + div & a) | (zee & b);
    let l: u128 = ((zee & b) - div & b) | (zee & a);
    let r: u128 = ((zee & a) + div & b) | (zee & a);
    [t,b,l,r]
}

fn zeeify(a: u128, b: u128) -> u128 {
    let mut f: u128 = 0;
    for i in 0..16 {
        f |= ((a & 1<<i) << i) | ((b & 1<<i) << i+1);
        //println!("{:b} {:b} | {:b} {:b} | {:b}", a, a&1<<i, b, b&1<<i, f);
    }
    f
}