Invitation to Eolymp Weekend Practice #18

Hello Codeforces!

I'm excited to invite you to Weekend Practice round #18 , taking place on 1st February, at 15:00 UTC. This is a rated contest at Eolymp.

Format and Difficulty

Same as in previous rounds, the competition is primarily aimed at improving practical skills. There will be $$$\LARGE \color{red}{\textbf{2}}$$$ hours for $$$5$$$ tasks of varying difficulty, the easiest of which can even be solved by beginners.

The scoring for each task being block-based (meaning points are awarded for each block of tests separately, and only if the solution passes all tests in the block). If there is a tie between two participants, the one whose last productive submission (i.e., a submission that added at least one point) was made earlier will be ranked higher in the leaderboard.

The statements will be available in the following languages: English, Ukrainian, Azerbaijani.

Registration

You can join the competition on the competition page.

Prizes

The winners of the contest will receive Eolymp Mints.

Criteria	Eolymp Mints
Top-$$$10$$$ (ranks $$$1$$$ to $$$10$$$)	$$$500$$$
$$$10$$$ random participants among Top-$$$50$$$ who scored at least $$$151$$$ points	$$$250$$$
$$$20$$$ random participants among Top-$$$100$$$ who scored at least $$$51$$$ points	$$$100$$$

Visit Frequently Asked Questions section to learn more.

Credits

MathModel For Coordinating The Round.
Sergey Kolodyazhnyy for creating Eolymp 😎.
Davy_D._Kaosar , De3b0o , TaklaOI for authoring Problems.
Connectus for Ukrainian Translations.
Davy_D._Kaosar, kimononawa , arpit_kr , Mohammed_Nasserr and chyckchyryk , Aritro_ , Ramen for testing the contest.

Scoring

$$$\Large {50-150-200-300-500}$$$

Congrats to Winners

Congrats to First Solvers

A : TheFuturoma

B : physics0523

C : Horka

D : potato167

E : potato167

Editorials

Comments (11)

Write comment?

Davy_D._Kaosar

3 months ago, hide # |

As an author I hope you will enjoy the problems :)

→ Reply

Mohammed_Nasserr

As a Tester I hope you to enjoy ^_^

kimononawa

omg we got speedrunning eolymp wp before gta VI

MathModel

← Rev. 2 →

Auto comment: topic has been updated by MathModel (previous revision, new revision, compare).

Time Reset Back to 2 Hours.

2 months ago, hide # |

Contest Starts in $$$4$$$ Hours.

Ramen

As a tester I hope you enjoy the round.

Starts in $$$20$$$ minutes

Aritro_

As a tester, I forgot to make an "As a tester" comment

lgrandco

spent the whole contest trying to not get MLE for the C (mex) in python :(, my approach was

code

import sys

input = sys.stdin.readline
print = lambda x: sys.stdout.write(str(x) + "\n")

d = {}
s = set()
for t in range(int(input())):
    d.clear()
    n, k = map(int, input().split())
    for _ in range(n):
        a = list(map(int, input().split()))
        s.clear()
        for i in range(1, a[0] + 1):
            e = a[i]
            if e == k:
                break
            if e < k:
                s.add(e)
        for e in s:
            if e < k:
                if e not in d:
                    d[e] = _
                else:
                    d[e] = None
    s.clear()
    r = "YES"
    for i in range(k):
        if i not in d:
            r = "NO"
            break
        elif d[i] is not None:
            s.add(d[i])
    if len(s) > n - 1:
        r = "NO"
    print(r)

Was there a more memory friendly approach (I also tried arrays of length k without more success) ?

2 months ago, hide # ^ |

Hi , I think you've used PyPy for the submissions in contest , I just submitted with Python $$$3.13$$$ and it passed in $$$640\text{ms}$$$

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