CashRegister.js

const currencyUnit = {
  PENNY: 1,
  NICKEL: 5,
  DIME: 10,
  QUARTER: 25,
  ONE: 100,
  FIVE: 500,
  TEN: 1000,
  TWENTY: 2000,
  "ONE HUNDRED": 10000,
};

function checkCashRegister(price, cash, cid) {
  let changeSum = cash * 100 - price * 100;
  let changeSumCheck = changeSum;
  let change = [];
  let status = "";

  let cidSum = 0;
  let filteredCid = cid.filter((elem) => elem[1] !== 0).reverse();

  filteredCid.forEach((elem) => {
    let curr = elem[0];
    let currSum = elem[1] * 100;
    cidSum += currSum;
    let amount = 0;
    while (changeSum >= currencyUnit[curr] && currSum > 0) {
      amount += currencyUnit[curr];
      changeSum -= currencyUnit[curr];
      currSum -= currencyUnit[curr];
    }
    if (amount !== 0) {
      change.push([curr, amount / 100]);
    }
  });

  if (changeSum > 0) {
    status = "INSUFFICIENT_FUNDS";
    change = [];
  } else if (changeSum == 0 && changeSumCheck == cidSum) {
    status = "CLOSED";
    change = cid;
  } else {
    status = "OPEN";
  }

  return { status: status, change: change };
}

checkCashRegister(19.5, 20, [
  ["PENNY", 1.01],
  ["NICKEL", 2.05],
  ["DIME", 3.1],
  ["QUARTER", 4.25],
  ["ONE", 90],
  ["FIVE", 55],
  ["TEN", 20],
  ["TWENTY", 60],
  ["ONE HUNDRED", 100],
]);