Tower of Hanoi in JS

hnt.js

const MAX_SIZE = 5

let a = [5, 4, 3, 2, 1],
  b = [],
  c = [];

let abc = {
  a,
  b,
  c
}

function repeat_str(s, n) {
  return Array(n).fill(s).join('')
}

function hnt(keys, n) {
  let key0 = keys[0],
    key1 = keys[1],
    key2 = keys[2];

  if (n === 1) {
    let tip = `from ${key0} to ${key2}`
    let k = abc[key0].pop()
    abc[key2].push(k)
    console.log(`${tip} moving ${k}`)

    console.log(`after moving: a:[${abc.a}] b:[${abc.b}] c:[${abc.c}]`)
  } else {
    console.log(repeat_str('|', MAX_SIZE - n) + repeat_str('-', 20))

    let move1 = `${keys[0]}${keys[2]}${keys[1]}`;
    console.log(`hnt(${move1},${n-1})`)
    hnt(move1, n - 1)

    let move2 = `${keys[0]}${keys[1]}${keys[2]}`;
    console.log(`hnt(${move2},1)`)
    hnt(move2, 1)

    let move3 = `${keys[1]}${keys[0]}${keys[2]}`;
    console.log(`hnt(${move3},${n-1})`)
    hnt(move3, n - 1)

    console.log(repeat_str('|', MAX_SIZE - n) + repeat_str('-', 20))
  }
}

hnt("abc", 5)

hnt.log

-------------------- 
hnt(acb,4) 
|-------------------- 
hnt(abc,3) 
||-------------------- 
hnt(acb,2) 
|||-------------------- 
hnt(abc,1) 
from a to c moving 1 
after moving: a:[5,4,3,2] b:[] c:[1] 
hnt(acb,1) 
from a to b moving 2 
after moving: a:[5,4,3] b:[2] c:[1] 
hnt(cab,1) 
from c to b moving 1 
after moving: a:[5,4,3] b:[2,1] c:[] 
|||-------------------- 
hnt(abc,1) 
from a to c moving 3 
after moving: a:[5,4] b:[2,1] c:[3] 
hnt(bac,2) 
|||-------------------- 
hnt(bca,1) 
from b to a moving 1 
after moving: a:[5,4,1] b:[2] c:[3] 
hnt(bac,1) 
from b to c moving 2 
after moving: a:[5,4,1] b:[] c:[3,2] 
hnt(abc,1) 
from a to c moving 1 
after moving: a:[5,4] b:[] c:[3,2,1] 
|||-------------------- 
||-------------------- 
hnt(acb,1) 
from a to b moving 4 
after moving: a:[5] b:[4] c:[3,2,1] 
hnt(cab,3) 
||-------------------- 
hnt(cba,2) 
|||-------------------- 
hnt(cab,1) 
from c to b moving 1 
after moving: a:[5] b:[4,1] c:[3,2] 
hnt(cba,1) 
from c to a moving 2 
after moving: a:[5,2] b:[4,1] c:[3] 
hnt(bca,1) 
from b to a moving 1 
after moving: a:[5,2,1] b:[4] c:[3] 
|||-------------------- 
hnt(cab,1) 
from c to b moving 3 
after moving: a:[5,2,1] b:[4,3] c:[] 
hnt(acb,2) 
|||-------------------- 
hnt(abc,1) 
from a to c moving 1 
after moving: a:[5,2] b:[4,3] c:[1] 
hnt(acb,1) 
from a to b moving 2 
after moving: a:[5] b:[4,3,2] c:[1] 
hnt(cab,1) 
from c to b moving 1 
after moving: a:[5] b:[4,3,2,1] c:[] 
|||-------------------- 
||-------------------- 
|-------------------- 
hnt(abc,1) 
from a to c moving 5 
after moving: a:[] b:[4,3,2,1] c:[5] 
hnt(bac,4) 
|-------------------- 
hnt(bca,3) 
||-------------------- 
hnt(bac,2) 
|||-------------------- 
hnt(bca,1) 
from b to a moving 1 
after moving: a:[1] b:[4,3,2] c:[5] 
hnt(bac,1) 
from b to c moving 2 
after moving: a:[1] b:[4,3] c:[5,2] 
hnt(abc,1) 
from a to c moving 1 
after moving: a:[] b:[4,3] c:[5,2,1] 
|||-------------------- 
hnt(bca,1) 
from b to a moving 3 
after moving: a:[3] b:[4] c:[5,2,1] 
hnt(cba,2) 
|||-------------------- 
hnt(cab,1) 
from c to b moving 1 
after moving: a:[3] b:[4,1] c:[5,2] 
hnt(cba,1) 
from c to a moving 2 
after moving: a:[3,2] b:[4,1] c:[5] 
hnt(bca,1) 
from b to a moving 1 
after moving: a:[3,2,1] b:[4] c:[5] 
|||-------------------- 
||-------------------- 
hnt(bac,1) 
from b to c moving 4 
after moving: a:[3,2,1] b:[] c:[5,4] 
hnt(abc,3) 
||-------------------- 
hnt(acb,2) 
|||-------------------- 
hnt(abc,1) 
from a to c moving 1 
after moving: a:[3,2] b:[] c:[5,4,1] 
hnt(acb,1) 
from a to b moving 2 
after moving: a:[3] b:[2] c:[5,4,1] 
hnt(cab,1) 
from c to b moving 1 
after moving: a:[3] b:[2,1] c:[5,4] 
|||-------------------- 
hnt(abc,1) 
from a to c moving 3 
after moving: a:[] b:[2,1] c:[5,4,3] 
hnt(bac,2) 
|||-------------------- 
hnt(bca,1) 
from b to a moving 1 
after moving: a:[1] b:[2] c:[5,4,3] 
hnt(bac,1) 
from b to c moving 2 
after moving: a:[1] b:[] c:[5,4,3,2] 
hnt(abc,1) 
from a to c moving 1 
after moving: a:[] b:[] c:[5,4,3,2,1] 
|||-------------------- 
||-------------------- 
|-------------------- 
--------------------