Kevin Wu kevinwucodes

Common Utilities Cheatsheet

Get SSL cert chain information (use https://tools.keycdn.com/ssl to verify chain)

openssl s_client -host XXX -port XXX -prexit -showcerts

Daily Coding Problem: Problem #81

Good morning! Here's your coding interview problem for today.

This problem was asked by Yelp.

Given a mapping of digits to letters (as in a phone number), and a digit string, return all possible letters the number could represent. You can assume each valid number in the mapping is a single digit.

For example if {“2”: [“a”, “b”, “c”], 3: [“d”, “e”, “f”], …} then “23” should return [“ad”, “ae”, “af”, “bd”, “be”, “bf”, “cd”, “ce”, “cf"].

Good morning! Here's your coding interview problem for today.

This problem was asked by Facebook.

Given a list of integers, return the largest product that can be made by multiplying any three integers.

For example, if the list is [-10, -10, 5, 2], we should return 500, since that's -10 * -10 * 5.

You can assume the list has at least three integers.

Good morning! Here's your coding interview problem for today.

This problem was asked by Amazon.

Given a N by M matrix of numbers, print out the matrix in a clockwise spiral.

For example, given the following matrix:

[[1,  2,  3,  4,  5],

[6, 7, 8, 9, 10],

Good morning! Here's your coding interview problem for today.

This problem was asked by Microsoft.

Given a 2D matrix of characters and a target word, write a function that returns whether the word can be found in the matrix by going left-to-right, or up-to-down.

For example, given the following matrix:

[['F', 'A', 'C', 'I'],

Good morning! Here's your coding interview problem for today.

This problem was asked by Palantir.

Write an algorithm to justify text. Given a sequence of words and an integer line length k, return a list of strings which represents each line, fully justified.

More specifically, you should have as many words as possible in each line. There should be at least one space between each word. Pad extra spaces when necessary so that each line has exactly length k. Spaces should be distributed as equally as possible, with the extra spaces, if any, distributed starting from the left.

If you can only fit one word on a line, then you should pad the right-hand side with spaces.

Good morning! Here's your coding interview problem for today.

This problem was asked by Microsoft.

Compute the running median of a sequence of numbers. That is, given a stream of numbers, print out the median of the list so far on each new element.

Recall that the median of an even-numbered list is the average of the two middle numbers.

For example, given the sequence [2, 1, 5, 7, 2, 0, 5], your algorithm should print out:

Good morning! Here's your coding interview problem for today.

This problem was asked by Amazon.

Run-length encoding is a fast and simple method of encoding strings. The basic idea is to represent repeated successive characters as a single count and character. For example, the string "AAAABBBCCDAA" would be encoded as "4A3B2C1D2A".

Implement run-length encoding and decoding. You can assume the string to be encoded have no digits and consists solely of alphabetic characters. You can assume the string to be decoded is valid.

function decode(input) {

	--taken directly from https://blogs.msdn.microsoft.com/simonince/2007/10/17/hierarchies-with-common-table-expressions/
	--order logic taken from https://stackoverflow.com/questions/32858774/how-to-order-rows-by-hierarchy

	/*
	Org chart
	----------
	matt (1)
	kirk (2)
	chris (3)
	tom (4)

	select *
	from (
	values
	(1, 1, 156.32, 1)
	,(null, 2, 468.96, 1)
	) s (r1, r2, amount, id)

	select *
	from (
	values