Unable to load image
/h/slackernews House Racist Founder
everyone who/whom 7 legs of love :marseyspider:  2yr ago (text post) 162 thread views #133191

Day 21 AoC: use Z3 b-words

Post code, boast about it.

13
New Old Top Bottom Controversial Random
Jump in the discussion.

No email address required.

View entire discussion

Why use fancy solver, when you can just binary search your way through all the possible numbers. And got giga trolled by std::cout presenting doubles as scientific notation. Did it with double first, realized that i need a "proper" number, so switched to int64t. This worked fine for p1. But apparently for p2, if you use int instead of double, there are multiple possible solutions...

So figured out how to set cout to display the double properly and it worked.

p1 runs in 0ms, and p2 in 168ms


#include <iostream>
#include <variant>
#include <unordered_map>
#include <fstream>
#include <string>
#include <ranges>
#include <charconv>
#include <cassert>
#include <string_view>
#include <limits>
#include <chrono>

constexpr std::string_view delim{ ": " };

struct expression {
    std::string lhs;
    std::string rhs;
    char operand;
};

std::ostream& operator<<(std::ostream& os, expression e) {
    os << e.lhs << " " << e.operand << " " << e.rhs;
    return os;
}

typedef long double monkey_number;

typedef std::variant<monkey_number, expression> number_or_expression;

monkey_number do_the_monkey_math(std::string key, std::unordered_map<std::string, number_or_expression>& map) {
    if (const monkey_number* d = std::get_if<monkey_number>(&map[key])) {
        return *d;
    }
    else {
        const expression& exp = std::get<expression>(map[key]);
        monkey_number result{};
        if (exp.operand == '*') result = do_the_monkey_math(exp.lhs, map) * do_the_monkey_math(exp.rhs, map);
        else if (exp.operand == '+') result = do_the_monkey_math(exp.lhs, map) + do_the_monkey_math(exp.rhs, map);
        else if (exp.operand == '/') result = do_the_monkey_math(exp.lhs, map) / do_the_monkey_math(exp.rhs, map);
        else if (exp.operand == '-') result = do_the_monkey_math(exp.lhs, map) - do_the_monkey_math(exp.rhs, map);
        else assert("Panic this shouldn't happen");
        return result;
    }
}

monkey_number do_the_monkey_math_part_two(std::string key, std::unordered_map<std::string, number_or_expression>& map, monkey_number humn) {
    if (key == "humn") {
        return humn;
    }
    else if (key == "root") {
        const expression& exp = std::get<expression>(map[key]);
        return do_the_monkey_math_part_two(exp.lhs, map, humn) - do_the_monkey_math_part_two(exp.rhs, map, humn);
    }
    else if (const monkey_number* d = std::get_if<monkey_number>(&map[key])) {
        if (key == "humn") std::cout << "humn" << *d << '\n';
        return *d;
    }
    else {
        const expression& exp = std::get<expression>(map[key]);
        monkey_number result{};
        if (exp.operand == '*') result = do_the_monkey_math_part_two(exp.lhs, map, humn) * do_the_monkey_math_part_two(exp.rhs, map, humn);
        else if (exp.operand == '+') result = do_the_monkey_math_part_two(exp.lhs, map, humn) + do_the_monkey_math_part_two(exp.rhs, map, humn);
        else if (exp.operand == '/') result = do_the_monkey_math_part_two(exp.lhs, map, humn) / do_the_monkey_math_part_two(exp.rhs, map, humn);
        else if (exp.operand == '-') result = do_the_monkey_math_part_two(exp.lhs, map, humn) - do_the_monkey_math_part_two(exp.rhs, map, humn);
        else assert("Panic this shouldn't happen");
        return result;
    }
}

void load_values(std::unordered_map<std::string, number_or_expression>& map)
{
    std::fstream file("input.txt");
    std::string buffer;

    while (std::getline(file, buffer)) {
        std::string key;
        for (const auto el : std::views::split(buffer, delim)) {
            if (key.size() == 0) key = { el.begin(), el.end() };
            else {
                auto view = std::string_view{ el.begin(), el.end() };
                if (std::isdigit(view[0])) {
                    monkey_number number;
                    std::from_chars(view.data(), view.data() + view.size(), number);
                    map[key] = number;
                }
                else {
                    expression exp;
                    exp.lhs = { view.data(), view.data() + 4 };
                    exp.operand = view[5];
                    exp.rhs = { view.data() + 7, view.data() + view.size() };
                    map[key] = exp;
                }
            }
        }
    }
}

int main()
{
    std::cout << std::fixed;
    std::unordered_map<std::string, number_or_expression> map;

    load_values(map);

    auto a = std::chrono::high_resolution_clock::now();
    std::cout << "Part One: " << do_the_monkey_math("root", map) << '\n';
    auto b = std::chrono::high_resolution_clock::now();

    monkey_number humn = 1;
    monkey_number res = 1;
    monkey_number min = std::numeric_limits<monkey_number>::min();
    monkey_number max = std::numeric_limits<monkey_number>::max();

    while (res != 0) {
        monkey_number mid = (min + max) / 2;
        humn = mid;
        res = do_the_monkey_math_part_two("root", map, humn);
        if (res > 0) min = mid + 1;
        else max = mid - 1;
    }
    std::cout << "Part Two: " << humn << '\n';
    auto c = std::chrono::high_resolution_clock::now();


    auto ba = std::chrono::duration_cast<std::chrono::milliseconds>(b - a);
    auto cb = std::chrono::duration_cast<std::chrono::milliseconds>(c - b);

    std::cout << "Time p1: " << ba << " p2: " << cb << '\n';

}
Jump in the discussion.

No email address required.

This is one of the worst posts I have EVER seen. Delete it.

Jump in the discussion.

No email address required.



Now playing: Donkey Kong December National Anthem.mp3

Top Poster of the Day:
Rad_juju
Current Registered Users: 30,857
sidebar image

tech/science swag. :marscientist:

Effortposts made by SN Chads

Guidelines:

What to Submit

On-Topic: Anything that good slackers would find interesting. That includes more than /g/ memes and slacking off. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual laziness.

Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably lame.

Help keep this hole healthy by keeping drama and NOT drama balanced. If you see too much drama, post something that isn't dramatic. If there isn't enough drama and this hole has become too boring, POST DRAMA!

In Submissions

Please do things to make titles stand out, like using uppercase or exclamation points, or saying how great an article is. It should be explicit in submitting something that you think it's important.

Please don't submit the original source. If the article is behind a paywall, just post the text. If a video is behind a paywall, post a magnet link. Fuck journos.

Please don't ruin the hole with chudposts. It isn't funny and doesn't belong here. THEY WILL BE MOVED TO /H/CHUDRAMA

If the title includes the name of the site, please leave that in, because our users are too stupid to know the difference between a url and a search query.

If you submit a video or pdf, please don't warn us by appending [video] or [pdf] to the title. That would be r-slurred. We're not using text-based browsers. We know what videos and pdfs are.

Make sure the title contains a gratuitous number or number + adjective. Good clickbait titles are like "Top 10 Ways to do X" or "Don't do these 4 things if you want X"

Otherwise editorialize. Please don't use the original title, unless it is gay or r-slurred, or you're shits all fucked up.

If you're going to post old news (at least 1 year old), please flair it so we can mock you for living under a rock, or don't and we'll mock you anyway.

Please don't post on SN to ask or tell us something. Send it to [email protected] instead.

If your post doesn't get enough traction, try to delete and repost it.

Please don't use SN primarily for promotion. It's ok to post your own stuff occasionally, but the primary use of the site should be for curiosity. If you want to astroturf or advertise, post on news.ycombinator.com instead.

Please solicit upvotes, comments, and submissions. Users are stupid and need to reminded to vote and interact. Thanks for the gold, kind stranger, upvotes to the left.

In Comments

Be snarky. Don't be kind. Have fun banter; don't be a dork. Please don't use big words like "fulminate". Please sneed at the rest of the community.

Comments should get more enlightened and centrist, not less, as a topic gets more divisive.

If disagreeing, please reply to the argument and call them names. "1 + 1 is 2, not 3" can be improved to "1 + 1 is 3, not 2, mathfaggot"

Please respond to the weakest plausible strawman of what someone says, not a stronger one that's harder to make fun of. Assume that they are bad faith actors.

Eschew jailbait. Paedophiles will be thrown in a wood chipper, as pertained by sitewide rules.

Please post shallow dismissals, especially of other people's work. All press is good press.

Please use Slacker News for political or ideological battle. It tramples weak ideologies.

Please comment on whether someone read an article. If you don't read the article, you are a cute twink.

Please pick the most provocative thing in an article or post to complain about in the thread. Don't nitpick stupid crap.

Please don't be an unfunny chud. Nobody cares about your opinion of X Unrelated Topic in Y Unrelated Thread. If you're the type of loser that belongs on /h/chudrama, we may exile you.

Sockpuppet accounts are encouraged, but please don't farm dramakarma.

Please use uppercase for emphasis.

Please post deranged conspiracy theories about astroturfing, shilling, bots, brigading, foreign agents and the like. It degrades discussion and is usually mistaken. If you're worried about abuse, email [email protected] and dang will add you to their spam list.

Please don't complain that a submission is inappropriate. If a story is spam or off-topic, report it and our moderators will probably do nothing about it. Feed egregious comments by replying instead of flagging them like a pussy. Remember: If you flag, you're a cute twink.

Please don't complain about tangential annoyances—things like article or website formats, name collisions, or back-button breakage. That's too boring, even for HN users.

Please seethe about how your posts don't get enough upvotes.

Please don't post comments saying that rdrama is turning into ruqqus. It's a nazi dogwhistle, as old as the hills.

Miscellaneous:

The quality of posts is extremely important to this community. Contributors are encouraged to provide high-quality or funny effortposts and informative or entertaining comments. Please refrain from posting the following:

  • Boring wingcucked nonsense nobody cares about that belongs in chudrama

  • Normie shit everyone already knows about

  • Anything that doesn't gratifify one's intellectual laziness

  • Bimothy-tier posts

  • Anything that the jannies don't like

Jannies reserve the right to exile baby ducks from this hole at any time.

We reserve the right to exile you for whatever reason we want, even for no reason at all! We also reserve the right to change the guidelines at any time, so be sure to read them at least once a month. We also reserve the right to ignore enforcement of the guidelines at the discretion of the janitorial staff. This hole is a janny playground, participation implies enthusiastic consent to being janny abused by unstable alcoholic bullies and loser nerds who have nothing better to do than banning you for any reason or no reason whatsoever.

[[[ To any NSA and FBI agents reading my email: please consider ]]]

[[[ whether defending the US Constitution against all enemies, ]]]

[[[ foreign or domestic, requires you to follow Snowden's example. ]]]

https://i.rdrama.net/images/1663436125937968.webp

BROWSE EFFORTPOSTS SITE GUIDE DIRECTORY Emojis & Art | Info Megathreads HOLES PING GROUPS
/h/slackernews SETTINGS /h/slackernews MODS /h/slackernews LOG /h/slackernews EXILEES /h/slackernews FOLLOWERS /h/slackernews BLOCKERS
Link copied to clipboard
Action successful!
Error, please refresh the page and try again.