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Cash Register

curriculum/challenges/english/blocks/javascript-algorithms-and-data-structures-projects/aa2e6f85cab2ab736c9a9b24.md

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--description--

Design a cash register drawer function checkCashRegister() that accepts purchase price as the first argument (price), payment as the second argument (cash), and cash-in-drawer (cid) as the third argument.

cid is a 2D array listing available currency.

The checkCashRegister() function should always return an object with a status key and a change key.

Return {status: "INSUFFICIENT_FUNDS", change: []} if cash-in-drawer is less than the change due, or if you cannot return the exact change.

Return {status: "CLOSED", change: [...]} with cash-in-drawer as the value for the key change if it is equal to the change due.

Otherwise, return {status: "OPEN", change: [...]}, with the change due in coins and bills, sorted in highest to lowest order, as the value of the change key.

<table><tbody><tr><th>Currency Unit</th><th>Amount</th></tr><tr><td>Penny</td><td>$0.01 (PENNY)</td></tr><tr><td>Nickel</td><td>$0.05 (NICKEL)</td></tr><tr><td>Dime</td><td>$0.1 (DIME)</td></tr><tr><td>Quarter</td><td>$0.25 (QUARTER)</td></tr><tr><td>Dollar</td><td>$1 (ONE)</td></tr><tr><td>Five Dollars</td><td>$5 (FIVE)</td></tr><tr><td>Ten Dollars</td><td>$10 (TEN)</td></tr><tr><td>Twenty Dollars</td><td>$20 (TWENTY)</td></tr><tr><td>One-hundred Dollars</td><td>$100 (ONE HUNDRED)</td></tr></tbody></table>

See below for an example of a cash-in-drawer array:

js
[
  ["PENNY", 1.01],
  ["NICKEL", 2.05],
  ["DIME", 3.1],
  ["QUARTER", 4.25],
  ["ONE", 90],
  ["FIVE", 55],
  ["TEN", 20],
  ["TWENTY", 60],
  ["ONE HUNDRED", 100]
]

--hints--

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]]) should return an object.

js
assert.deepEqual(
  Object.prototype.toString.call(
    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]
    ])
  ),
  '[object Object]'
);

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]]) should return {status: "OPEN", change: [["QUARTER", 0.5]]}.

js
assert.deepEqual(
  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]
  ]),
  { status: 'OPEN', change: [['QUARTER', 0.5]] }
);

checkCashRegister(3.26, 100, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]) should return {status: "OPEN", change: [["TWENTY", 60], ["TEN", 20], ["FIVE", 15], ["ONE", 1], ["QUARTER", 0.5], ["DIME", 0.2], ["PENNY", 0.04]]}.

js
assert.deepEqual(
  checkCashRegister(3.26, 100, [
    ['PENNY', 1.01],
    ['NICKEL', 2.05],
    ['DIME', 3.1],
    ['QUARTER', 4.25],
    ['ONE', 90],
    ['FIVE', 55],
    ['TEN', 20],
    ['TWENTY', 60],
    ['ONE HUNDRED', 100]
  ]),
  {
    status: 'OPEN',
    change: [
      ['TWENTY', 60],
      ['TEN', 20],
      ['FIVE', 15],
      ['ONE', 1],
      ['QUARTER', 0.5],
      ['DIME', 0.2],
      ['PENNY', 0.04]
    ]
  }
);

checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]) should return {status: "INSUFFICIENT_FUNDS", change: []}.

js
assert.deepEqual(
  checkCashRegister(19.5, 20, [
    ['PENNY', 0.01],
    ['NICKEL', 0],
    ['DIME', 0],
    ['QUARTER', 0],
    ['ONE', 0],
    ['FIVE', 0],
    ['TEN', 0],
    ['TWENTY', 0],
    ['ONE HUNDRED', 0]
  ]),
  { status: 'INSUFFICIENT_FUNDS', change: [] }
);

checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 1], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]) should return {status: "INSUFFICIENT_FUNDS", change: []}.

js
assert.deepEqual(
  checkCashRegister(19.5, 20, [
    ['PENNY', 0.01],
    ['NICKEL', 0],
    ['DIME', 0],
    ['QUARTER', 0],
    ['ONE', 1],
    ['FIVE', 0],
    ['TEN', 0],
    ['TWENTY', 0],
    ['ONE HUNDRED', 0]
  ]),
  { status: 'INSUFFICIENT_FUNDS', change: [] }
);

checkCashRegister(19.5, 20, [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]) should return {status: "CLOSED", change: [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]]}.

js
assert.deepEqual(
  checkCashRegister(19.5, 20, [
    ['PENNY', 0.5],
    ['NICKEL', 0],
    ['DIME', 0],
    ['QUARTER', 0],
    ['ONE', 0],
    ['FIVE', 0],
    ['TEN', 0],
    ['TWENTY', 0],
    ['ONE HUNDRED', 0]
  ]),
  {
    status: 'CLOSED',
    change: [
      ['PENNY', 0.5],
      ['NICKEL', 0],
      ['DIME', 0],
      ['QUARTER', 0],
      ['ONE', 0],
      ['FIVE', 0],
      ['TEN', 0],
      ['TWENTY', 0],
      ['ONE HUNDRED', 0]
    ]
  }
);

--seed--

--seed-contents--

js
function checkCashRegister(price, cash, cid) {
  let change;
  return 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]]);

--solutions--

js
const denom = [
  { name: "ONE HUNDRED", val: 100 },
  { name: "TWENTY", val: 20 },
  { name: "TEN", val: 10 },
  { name: "FIVE", val: 5 },
  { name: "ONE", val: 1 },
  { name: "QUARTER", val: 0.25 },
  { name: "DIME", val: 0.1 },
  { name: "NICKEL", val: 0.05 },
  { name: "PENNY", val: 0.01 },
];

function checkCashRegister(price, cash, cid) {
  const output = { status: null, change: [] };
  let change = cash - price;
  const register = cid.reduce(
    function (acc, curr) {
      acc.total += curr[1];
      acc[curr[0]] = curr[1];
      return acc;
    },
    { total: 0 }
  );
  if (register.total === change) {
    output.status = "CLOSED";
    output.change = cid;
    return output;
  }
  if (register.total < change) {
    output.status = "INSUFFICIENT_FUNDS";
    return output;
  }
  const change_arr = denom.reduce(function (acc, curr) {
    let value = 0;
    while (register[curr.name] > 0 && change >= curr.val) {
      change -= curr.val;
      register[curr.name] -= curr.val;
      value += curr.val;
      change = Math.round(change * 100) / 100;
    }
    if (value > 0) {
      acc.push([curr.name, value]);
    }
    return acc;
  }, []);
  if (change_arr.length < 1 || change > 0) {
    output.status = "INSUFFICIENT_FUNDS";
    return output;
  }
  output.status = "OPEN";
  output.change = change_arr;
  return output;
}