Minimum required coins to reach the given input amount

giveCoins.js

/*
    Task: Minimum required coins to reach the given input amount
    Given a list of coins: 500, 200, 100, 50, 20, 10, 2, 1, 0.5, 0.2, 0.1, 0.02, 0.01
    Given input amount: 3763.58

    Expected output:

    {
        500:7,
        200:1,
        100:0,
        50:1,
        20:0,
        10:1,
        2:1,
        1:1,
        0.5:1,
        0.2:0,
        0.1:0,
        0.02:4,
        0.01:0
    }
*/
const cache = {};

// console.log(giveCoins([10, 4, 3, 0.01], 5));
console.log(giveCoins([500, 200, 100, 50, 20, 10, 2, 1, 0.5, 0.2, 0.1, 0.02, 0.01], 3763.58));


function giveCoins(coins, amount) {
  if (coins.some(coin => coin < 1)) {
    const result = giveCoins(coins.map(coin => coin * 100), amount * 100)

    return Object.fromEntries(Object.entries(result).map(([coin, count]) => [coin / 100, count]))
  }

  const key = coins.toString()
  const results = cache[key] || {}

  cache[key] = results

  return iter(amount)

  function iter(amount) {
    if (results[amount]) return results[amount] 

    if (amount === 0) return {}

    const i = coins.findIndex(coin => coin <= amount)

    if (i === -1) throw new Error('impossible')
    
    const slice = coins.slice(i)

    for (const coin of slice) {
      try {
        const result = add({[coin]: 1}, iter(amount - coin))

        results[amount] = result
        return result
      } catch {}
    } 

    throw new Error('impossible')
  }
}

function add(obj1, obj2) {
  const result = {...obj1}

  for (const key in obj2) result[key] = (result[key] || 0) + obj2[key] 

  return result
}