Lovecraft: solve

lib.rs

use std::collections::HashMap;
use std::collections::VecDeque;

pub fn solve(grid: Grid) -> Vec<Pos> {
    if is_solved(grid){
        return vec!();
    }
    let mut ret = None;
    
    let mut seen=HashMap::new();
    seen.insert(grid,Vec::new());
    let mut todo=VecDeque::new();
    todo.push_back(grid);

    while ret.is_none(){
        match todo.pop_front(){
            Some(g)=> {
                ret = try_all(&g,&mut seen,&mut todo);
            },
            None=>panic!("no more grids to do"),
        }
       
    }
    ret.expect("no result!")
}