Sujeet Agrahari sujeet-agrahari

Inspired by this article. Neat tricks for speeding up integer computations.

Note: cin.sync_with_stdio(false); disables synchronous IO and gives you a performance boost. If used, you should only use cin for reading input (don't use both cin and scanf when sync is disabled, for example) or you will get unexpected results.

Multiply by a power of 2

x = x << 1; // x = x * 2

If you spend the next twenty years of your life, you could do something like a Michael Angelo painting, would it be worth it? Of course it would. It would be worth it for that one thing. For things to be worthwhile, they should be difficult.

Joe Armstrong

For every power user that writes in asking for a feature, there’s one new user (and ten potential users) that felt the opposite way.

Ben Balter

When you’re evaluating potential features, part of your role is to be an advocate for the long tail of users that won’t yet advocate for themselves.

OAUTH2

The Problem

I’m a web app that wants to allow other web apps access to my users’ information, but I want to ensure that the user says it’s ok.

The Solution

I can’t trust the other web apps, so I must interact with my users directly. I’ll let them know that the other app is trying to get their info, and ask whether they want to grant that permission. Oauth defines a way to initiate that permission verification from the other app’s site so that the user experience is smooth. If the user grants permission, I issue an AuthToken to the other app which it can use to make requests for that user's info.

Note on encryption

Oauth2 has nothing to do with encryption -- it relies upon SSL to keep things (like the client app’s shared_secret) secure.

	// get transaction
	const transaction = await sequelize.transaction();
	try {
	// step 1
	await Model.destroy({where: {id}}, {transaction});

	// step 2
	await Model.create({}, {transaction});

	// commit

	A.hasOne(B, { otpions} ) //foreign key is in B :Aid

	A.belongsTo(B, { options}) //foreign key is in A :Bid

	A.hasMany(B, { options}) /foreign key is in B : Aid


	//These three calls will cause Sequelize to automatically add foreign keys to the appropriate models (unless they are already present).
	A.belongsToMany(B, {through: 'C' options})

	Here is another solution to having related schemas for GET/POST/PATCH, using destructuring and optionalKeys:

	const fooCommonFields = {
	a: Joi.string().required(),
	b: Joi.string().required(),
	}

	// On POST, all common fields are required
	const fooCreateSchema = Joi.object({
	...fooCommonFields,

	// sending to sender-client only
	socket.emit('message', "this is a test");

	// sending to all clients, include sender
	io.emit('message', "this is a test");

	// sending to all clients except sender
	socket.broadcast.emit('message', "this is a test");

	// sending to all clients in 'game' room(channel) except sender

	// sending to sender-client only
	socket.emit('message', "this is a test");

	// sending to all clients, include sender
	io.emit('message', "this is a test");

	// sending to all clients except sender
	socket.broadcast.emit('message', "this is a test");

	// sending to all clients in 'game' room(channel) except sender


	module.exports = {
	apps: [
	{
	name: 'Express App',
	script: './src/server.js',
	instances: 'MAX',
	autorestart: false,
	watch: true,
	max_memory_restart: '1G',

	https://stackoverflow.com/questions/37723420/convert-datetime-to-date-of-a-column-in-where-condition-using-sequelize
	Event.findAll({
	where: sequelize.where(sequelize.fn('date', sequelize.col('event_date')), '<=', '2016-10-10')
	})

	{
	where: {
	[Sequelize.Op.and]: [{
	id: 45
	}, Sequelize.where('date', '=', '2018-05-13')]