Asklemmy

43962 readers

1495 users here now

A loosely moderated place to ask open-ended questions

Search asklemmy 🔍

If your post meets the following criteria, it's welcome here!

Open-ended question
Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
Not ad nauseam inducing: please make sure it is a question that would be new to most members
An actual topic of discussion

Looking for support?

Looking for a community?

Lemmyverse: community search
sub.rehab: maps old subreddits to fediverse options, marks official as such
!lemmy411@lemmy.ca: a community for finding communities

~Icon~ ~by~ ~@Double_A@discuss.tchncs.de~

founded 5 years ago

MODERATORS

Is it possible for devices on an online group chat to toss a coin without trusting each other and the server? (discuss.tchncs.de)

submitted 6 months ago by smileyhead@discuss.tchncs.de to c/asklemmy@lemmy.ml

41 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] tetris11@lemmy.ml 2 points 6 months ago

Second attempt that factors in cheating.

spoiler

from numpy import median
from random import choice
from pprint import pprint

# Functions
get_mode_coin = lambda x: int(median(x))
def pick(player, wants):
    for neighbor in players:
        if player != neighbor:
            neighbor_purse = players[neighbor]["purse"]
            if wants:
                if wants in neighbor_purse: # Cheat
                    players[play]["purse"] = players[play]["purse"] + [wants]
                    continue
            players[play]["purse"] = players[play]["purse"] + [choice(neighbor_purse)]


# Main
players = {"p1" : {"purse": [1,0,1], "wants": False}, ## playing fair
           "p2" : {"purse": [0,0,1], "wants": 0}, ## cheating
           "p3" : {"purse": [1,1,0], "wants": 1}, ## cheating
           "p4" : {"purse": [1,1,0], "wants": 0}, ## cheating
           "p5" : {"purse": [0,0,1], "wants": False}}   ## playing fair

for play in players: ## Players pick a desired coin from each of their neighbours
    pick(play, players[play]["wants"])
print("First picks:")
pprint(players)

for play in players: ## Players collapse their collections to mode
    players[play] = [get_mode_coin(players[play]["purse"])]
print("Last modes:", players)

print("Final choice:", get_mode_coin([x for x in players.values()]))

So, my method doesn't work