Y'all are surprising me with your programming opinions
Then again, JavaScript or whatever apparently has a Math.max function, while C doesn't
@vaporeon_ software eggineering poisons your brain
@wallhackio Are you referring to yourself or to me or to us all?
@vaporeon_ I'm referring to anyone who writes code for money instead of writing code for fun
@vaporeon_ this is not a slight on Holly. i hope that is clear. she does code golf so you know she actually likes coding for the hell of it
@wallhackio @vaporeon_ oh yeah all this goes out the window when you're golfing. sometimes it's fun to let loose and write some horseshit
@monorail @vaporeon_ my worst code practices occur when i hack a solution to a challenging data structures/algorithms problem
@wallhackio How can you have bad code practices when there's no such thing as good Java code, it's all terrible
@vaporeon_ I've done DS&A problems in JavaScript and written some nightmarish oneliners doing that
@wallhackio Need to see 
@vaporeon_ I know how this is gonna go. I will show it to you and then you'll be like, wait this is cool I like it :)
@wallhackio I love how my Mastodon posting has made you use gorp, norp, and sorp in actual code
@wallhackio @vaporeon_ is that single member array of arrays not a typo lol
@aescling @vaporeon_ if you are wondering this is using the Dutch National Flag partition, which is the actual real name for it, and I simulated recursion using a stack (a JavaScript array has methods on it that allow it to easily resemble a stack)
I used the ninther strategy for the pivot selection but that was not present in this snippet
@aescling @vaporeon_ oh this was an inefficient implementation of Dutch National Flag too, lol
@wallhackio @aescling @vaporeon_ It's funny how "a JavaScript start has methods on it that allow it to easily resemble a stack" should immediately set off all kinds of red flags for anyone with basic algorithms knowledge, *and yet* because developers regularly use them like that, most JavaScript engines have developed to make those operations fast and otherwise efficient.
@aschmitz @aescling @vaporeon_ I once used a JavaScript array as a queue, using the shift method to pluck elements from the start of the array. Of course, this means iterating over an entire "queue" should be slow, since every call to shift causes every element in the array to be reassigned and reduces the size of the array by 1. I benchmarked my algorithm and it was slower than I hoped, so I immediately worked on the queue as I thought it was a throttle for the algorithm.
I made an object that effectively had a JavaScript array as a private variable and created a method for "removing" the first element from the array. In reality, there was pointer being tracked by the object that simply shifted to the right by 1, simulating the behavior of a queue with an ordinary array. Obviously iterating over this structure should be O(n).
To my surprise, when I benchmarked the algorithm again, it was slower. Evidently, with my first approach, the JIT engine realized I was using an array as a queue and secretly optimized it for me. Without realizing, I tried to outsmart the JIT engine, and lost.
@vaporeon_ here is another hack with a "beautiful" one liner:
Problem Statement
You are given a 0-indexed array of integers nums of length n. You are initially positioned at nums[0].
Each element nums[i] represents the maximum length of a forward jump from index i. In other words, if you are at nums[i], you can jump to any nums[i + j] where:
0 <= j <= nums[i]andi + j < n
Return the minimum number of jumps to reach nums[n - 1]. The test cases are generated such that you can reach nums[n - 1].
Example
- Input: nums =
[2,3,1,1,4] - Output:
2 - Explanation:
The minimum number of jumps to reach the last index is 2. Jump 1 step from index 0 to 1, then 3 steps to the last index.
Code
const jump = (nums, i = 0, gorp = {}) => {
if (i === nums.length - 1) return 0;
if (i > nums.length - 1 || nums[i] === 0) return Infinity;
if (gorp[i] !== undefined) return gorp[i];
let min = Infinity;
for (let j = 1, res; j <= nums[i]; ++j) res = 1 + jump(nums, i + j, gorp), min = res < min ? res : min;
return gorp[i] = min;
};
@wallhackio @vaporeon_ i think you omitted a closing parenthesis?
@aescling @vaporeon_ I just ran it and what is here is correct
@wallhackio @vaporeon_ oh i can't read, nvm
@vaporeon_ oooooh I could have done for (var min = Infinity, j = 1, res; j <= nums[i]; ++j) res = 1 + jump(nums, i + j, gorp), min = res < min ? res : min;
javascript variables declared with var and not block scoped, so min is available outside of the for loop teehee
@wallhackio @vaporeon_ that's awful i love it lol
@aescling @vaporeon_ ....it runs faster with this change
@wallhackio @vaporeon_ if you look into the semantic diffurences between for with let and var scoped variables, this is not surpurrising; the furmer is surpurrisingly complicated. const allows fur some optimizations over let though iirc
@aescling @vaporeon_ with let the algo ran the test cases ~700ms and with var it shaved ~100ms
@vaporeon_ look at this beauty:
var change = function(amount, coins) {
for (var i = 0, m = new Array(coins.length); i < coins.length; ++i) m[i] = new Array(amount + 1).fill(0), m[i][0] = 1;
for (var r = coins.length - 1; r >= 0; --r) for (var c = 1; c <= amount; ++c) for (x = r; x < coins.length; ++x) if (c - coins[x] >= 0) m[r][c] += m[x][c - coins[x]];
return m[0][amount];
};
@wallhackio What is an Array and why are we using that instead of just malloc-ing (or calloc-ing, if we want 0-initialization) some space? Also, what's up with the var, does it not have data-types like in C? Or is var like C++ auto?
@vaporeon_ @wallhackio this is javascript
Sorry, I didn't check which thread this was replying to, and thought this was an example of Go...
@vaporeon_ Array is the ordinary JavaScript array. using the constructor is abnormal but I know the exact size of the array so it is (probably) slightly more efficient to use the constructor so I can initialize it to an exact size.
in my experience var runs faster than let/const and its goofy scoping rules let me make the code more golfy. (I declare m in the first for loop and the return statement uses m! its terrible and i love it!!!!!!)
@wallhackio I'm sorry, I got confused and thought this was Go code
(Also, you should show me some Go code if you like it that much
Tell me of the cursed things that you can do in Go)
@vaporeon_ I don't know Go. I said I would probably like it, but that is a gut instinct based on, like, reading Wikipedia. I've never actually used it at all.
If I ever learn Go I will happily share horrendous code I make with it to 
@wallhackio Oh, OK... Then maybe @aescling can show me the worst Go code she has ever written?
@vaporeon_ @wallhackio i haven’t written any go
@vaporeon_ I tried rewriting it with let and const and there was no real impact on the speed
@vaporeon_ it is 100x slower than the optimal solution and it is Worth It
@vaporeon_ okay here's a bad one. i implemented a non-recursive quicksort using the variables gorp, norp, and sorp: