arr = [] // empty array
const isEmpty = arr => !Array.isArray(arr) || arr.length === 0;

// Examples
isEmpty([]); // true
isEmpty([1, 2, 3]); // false

const quickSort = arr => {
  const a = [...arr];
  if (a.length < 2) return a;
  const pivotIndex = Math.floor(arr.length / 2);
  const pivot = a[pivotIndex];
  const [lo, hi] = a.reduce(
    (acc, val, i) => {
      if (val < pivot || (val === pivot && i != pivotIndex)) {
        acc[0].push(val);
      } else if (val > pivot) {
        acc[1].push(val);
      }
      return acc;
    },
    [[], []]
  );
  return [...quickSort(lo), pivot, ...quickSort(hi)];
};

quickSort([1, 6, 1, 5, 3, 2, 1, 4]); // [1, 1, 1, 2, 3, 4, 5, 6]

var arr = [{
    "success": true,
    "data": [
        {
            "id": "ipi_1KrrbvDOiB2klwsKhuqUWqt1",
            "object": "issuing.transaction",
            "amount": -2743,
            "amount_details": {
                "atm_fee": null
            },
            "authorization": "iauth_1KrrbuDOiB2klwsKoFjQZhhd",
            "balance_transaction": "txn_1KrrbwDOiB2klwsK1YkjJJRi",
            "card": "ic_1Krqe5DOiB2klwsK44a35eiE",
            "cardholder": "ich_1KrqL8DOiB2klwsKtBnZhzYr",
            "created": 1650753567,
            "currency": "usd",
            "dispute": null,
            "livemode": false,
            "merchant_amount": -2743,
            "merchant_currency": "usd",
            "merchant_data": {
                "category": "advertising_services",
                "category_code": "7311",
                "city": "San Francisco",
                "country": "US",
                "name": "Aeros Marketing, LLC",
                "network_id": "1234567890",
                "postal_code": "94103",
                "state": "CA"
            },
            "metadata": {},
            "type": "capture",
            "wallet": null
        },
                {
            "id": "ipi_1Krrbvc62B2klwsKhuqUWqt1",
            "object": "issuing.transaction",
            "amount": -9999,
            "amount_details": {
                "atm_fee": null
            },
            "authorization": "iauth_1KrrbuDOiB2klwsKoFjQZhhd",
            "balance_transaction": "txn_1KrrbwDOiB2klwsK1YkjJJRi",
            "card": "ic_1Krqe5DOiB2klwsK44a35eiE",
            "cardholder": "ich_1KrqL8DOiB2klwsKtBnZhzYr",
            "created": 1650753567,
            "currency": "USD",
            "dispute": null,
            "livemode": false,
            "merchant_amount": -9999,
            "merchant_currency": "usd",
            "merchant_data": {
                "category": "fast_food",
                "category_code": "7311",
                "city": "San Francisco",
                "country": "US",
                "name": "Aeros Marketing, LLC",
                "network_id": "1234567890",
                "postal_code": "94103",
                "state": "CA"
            },
            "metadata": {},
            "type": "capture",
            "wallet": null
        }
    ]
}];
    

const reduced = arr.reduce((prev, curr) => {
    prev.push({
        amount: curr.data[0].merchant_amount,
        id: curr.data[0].id,
        currency: curr.data[0].currency,
        category: curr.data[0].merchant_data.category
    });
    console.log(prev)

    return prev;
    
}, []);

if (process.env.NODE_ENV === "production") {
	app.use(express.static("client/build"));

	app.get("*", (req, res) => {
	res.sendFile(path.resolve(__dirname, "client", "build", "index.html"));
	});
}

console.log("hello world")

// Time Complexity : O(N)
// Space Complexity : O(1)
 
var isMonotonic = function(nums) {
    let isMono = null;
    for(let i = 1; i < nums.length; i++) {
        if(isMono === null) {
            if(nums[i - 1] < nums[i]) isMono = 0;
            else if(nums[i - 1] > nums[i]) isMono = 1;
            continue;
        }
        if(nums[i - 1] < nums[i] && isMono !== 0) {
            return false;
        }
        else if(nums[i - 1] > nums[i] && isMono !== 1) {
            return false;
        }
    }
    
    return true;
    
};

let nums1 = [1,2,2,3]
let nums2 = [6,5,4,4]
let nums3 = [1,3,2]

console.log(isMonotonic(nums1));
console.log(isMonotonic(nums2));
console.log(isMonotonic(nums3));