function printHeap(heap, index, level) {
    if (index >= heap.length) {
        return;
    }
    console.log("  ".repeat(level) + heap[index]);
    printHeap(heap, 2 * index + 1, level + 1);
    printHeap(heap, 2 * index + 2, level + 1);
}

//You can call this function by passing in the heap array and the index of the root node, which is typically 0, and level = 0.

let heap = [3, 8, 7, 15, 17, 30, 35, 2, 4, 5, 9];
printHeap(heap,0,0)

// promisify(f, true) to get array of results
function promisify(f, manyArgs = false) {
  return function (...args) {
    return new Promise((resolve, reject) => {
      function callback(err, ...results) { // our custom callback for f
        if (err) {
          reject(err);
        } else {
          // resolve with all callback results if manyArgs is specified
          resolve(manyArgs ? results : results[0]);
        }
      }

      args.push(callback);

      f.call(this, ...args);
    });
  };
}

// usage:
f = promisify(f, true);
f(...).then(arrayOfResults => ..., err => ...);

router.post("/", async (req, res) => {
	const { email, password } = req.body;

	try {
	if (!email) return res.status(400).json({ msg: "An email is required" });

	if (!password)
	return res.status(400).json({ msg: "A password is required" });

	const user = await User.findOne({ email }).select("_id password");

	if (!user) return res.status(400).json({ msg: "Invalid credentials" });

	const match = await bcrypt.compare(password, user.password);

	if (!match) return res.status(400).json({ msg: "Invalid credentials" });

	const accessToken = genAccessToken({ id: user._id });
	const refreshToken = genRefreshToken({ id: user._id });

	res.cookie("token", refreshToken, {
	expires: new Date(Date.now() + 604800),
	httpOnly: true,
	});

	res.json({ accessToken });
	} catch (err) {
	console.log(err.message);
	res.status(500).json({ msg: "Error logging in user" });
	}
});

class SequentialQueue{	//if you want it to go backwards, too bad
	next(){
		return this.i++;
	}
	constructor(start = 0){
		this.i = start;
	}
}
const que = new SequentialQueue(0);
for(let i = 0; i < 10; i++){
	console.log(que.next());
}

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var productExceptSelf = function(nums) {
    var output = [];
    var leftMult = 1;
    var rightMult = 1;
    for (var i=nums.length - 1; i >= 0; i--) {
        output[i] = rightMult;
        rightMult *= nums[i];
        console.log({output: JSON.stringify(output), i})
    }
    for (var j=0; j < nums.length; j++) {
        output[j] *= leftMult;
        leftMult *= nums[j];
        console.log({output: JSON.stringify(output), j})
    }
    return output;
};

console.log(productExceptSelf([1, 2, 3, 4]))

const mongoose = require('mongoose')

const UserSchema = new mongoose.Schema({
	username: {
	type: String,
	required: true
	},
	email: {
	type: String,
	unique: true,
	required: true
	},
	password: {
	type: String,
	required: true
	},
	date: {
	type: Date,
	default: Date.now
	}
})

module.exports = User = mongoose.model('user', UserSchema)