All solutions need Node.js to run.
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( Credit Rosetta Code for explanation )
You make N passes by the doors. The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it). The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it. The third time, visit every 3rd door (door #3, #6, #9, ...), etc, until you only visit the Nth door.
What state are the doors in after the last pass? Which are open, which are closed?node ndoors.js [number-of-doors] -
( Credit Rosetta Code for explanation )
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression. The output can be anything, as long as you can recreate the input with it.
node runlength.js c [range-of-alphabets] //for compress. node runlength.js uc [range-of-alpha-numeric-values] //for un-compress.node runlength.js c DDDDDHHHHSSS gives you 5D4H3S node runlength.js uc 5D4H3S gives you DDDDDHHHHSSS -
( Credit Leetcode for explanation )
Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice.
node twosum.js [comma-separated-non-repeating-numbers] [target-number]node twosum.js 2,7,11,15 9 gives you [0,1] -
( Credit Leetcode for explanation )
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. You may assume the two numbers do not contain any leading zero, except the number 0 itself.
node addtwonumbers.js [first-hyphen-separated-numbers] [second-hyphen-separated-numbers]node addtwonumbers.js 2-4-3 5-6-4 gives you 7 -> 0 -> 8