Function initial 

pub fn initial(a: &[[usize; 2]], b: &mut Vec<[usize; 2]>)

Etches away initial nodes.

The first argument should be the solved maze. The second argument should be the original maze.

Examples found in repository

examples/line.rs (line 13)

fn main() {
    let n = 4;
    // 0 1 2 3
    let mut x = shapes::dir_line(n);
    while x.len() > 0 {
        let m = solve(x.clone());
        println!("{}", map::visualize(&map::map2([4, 1], &x)));
        println!("{:?}\n---------------------------------------\n{:?}\n", x, m);
        etch::initial(&m, &mut x);
    }
}