n-queens

めもめも

(number=>{

const init=width=>{

  const h=i=>~~(i/width), v=i=>i%width, d=i=>h(i)+v(i), u=i=>h(i)-v(i);

  const test=(grid,i,f)=>grid.filter((e,j)=>f(i)==f(j)).reduce((a,c)=>a+c,0) < 2;

  let count=0;

  const log=grid=>[...Array(width).keys()].map(e=>e*width).forEach(
    e=>((e==0)?console.log((++count)+":"+"-".repeat(width)):false)
     ||console.log(grid.slice(e,e+width))
  );

  return solve=(grid=[...Array(width**2)].fill(0),row=0)=>
    [...Array(width)].map((_,i)=>i+row*width).forEach(i=>[
      grid[i]=1,
      (test(grid,i,v)&&test(grid,i,d)&&test(grid,i,u))?
        (row+1==width?log(grid):solve(grid, row+1)):0,
      grid[i]=0
    ]);
};

init(number)();

})(8)