From Pierre Elliott Trudeau H.S., Canadian Computing Olympiad, University of Waterloo, Olympiads Computing Competition
About
List of problems that only admins can fix
Sorted by importance.
- Some IE submissions.
- In the submit editor, Python 3's code gets highlighted according to Python 2. e.g.
xrangegets highlighted although it doesn't exist in Python 3. (thanks, Ace editor) - Places that still use the old asymmetrical logo: GitHub, DMOJ's rotating Discord logo, 's JOMD bot on Discord, LinkedIn, Crowdin, Facebook, Docker, 's side project "DMOJ Docker Files"
- In the runtime page, the brain**** link should use https. Also, Forth's description shouldn't have
Gforth 0.7.2.. - In the submit editor, AWK, Pike, Turing, and Zig don't have code highlighting. (because the Ace repo doesn't have them)
- Turing syntax highlighting, relevant for aplusb and helloworld.
Easiest problems that I didn't solve yet: (problems modified after 2020-05-29 don't count)
Represented Dmojistan at IOI 2017.
Fun fact: Since 2022-07-17, the DMOJ logo became symmetrical.
#include <stdio.h>
char A[123][123];
int main()
{
void *p1=(A+1);
void *p2=*(A+1);
if (p1==p2) printf("yes\n");
}
a=[]
a.append(a)
print(a==[a])
print(a==a[0])
Math contest lottery winner (AMC 10B 2015).
Just wanted to say that there is a User-script thing when you edit your profile. Use it to prank someone.
After you're done, make sure to give them this link and tell them to erase the User-script.
$(function() {
// You have to credit d if you're going to use this
// Can't modify stuff now, right?
var elements = document.getElementsByTagName("li");
for (i=elements.length-1; i>=0; i--) {
var e=elements[i];
if (e.children.length===1) {
var f=e.children[0];
if (f.tagName.toUpperCase()==="A") {
if (f.text==="Edit profile") {
e.parentNode.removeChild(e);
}
else if (f.text==="Log out") {
e.parentNode.removeChild(e);
}
}
}
}
// Can't submit solutions now, right?
var links = document.getElementsByTagName("a");
for (i=links.length-1; i>=0; i--) {
var l=links[i];
if (l.text.toLowerCase()==="resubmit") {
l.href="/";
l.text="You cannot resubmit";
}
else if (l.text.toLowerCase()==="submit solution") {
l.href="/";
l.text="You cannot submit";
}
}
// Part 2 of solution submission code
inputs = document.getElementsByTagName("input");
for (var index=inputs.length-1; index>=0; index--) {
i=inputs[index];
if (i.hasAttribute("Value")) {
if (i.value.toLowerCase()==="submit!") {
i.disabled=true;
i.value="Submission unavailable";
}
}
}
});
function banned(){
setTimeout(function(){alert("YOU HAVE BEEN PERMANENTLY BANNED FROM DMOJ.")}, 2000);
}
banned();
My user-script:
$(document).ready(function(){
document.title = document.title.replace("DMOJ: Modern Online Judge", "DMOJ : Juge en Ligne Moderne"); // "Dank Memes Online Judge"
const f = s=>`<span style="background-color:rgba(247,196,0,0.5)">${s}</span>`;
$('code').html((i,obj) => obj
.replaceAll(/\w +\S/g,s=>s[0]+f(s.slice(1,-1))+s.slice(-1))
.replaceAll(/ +\n/g,s=>f(s.slice(0,-1))+'\n')
.replaceAll(/ +$/g,s=>f(s)+'\n'));
$('h2').click(() => {
$('td.user-name').map((i,td) => {if (td.children && td.children.length>1 && td.children[1].innerText==='Participation ended.') td.parentElement.remove();});
$('td.user-name').map((i,td) => {if (td.children && td.children.length>1 && td.children[1].innerText!=='Participation ended.') {const a=td.children[0].children[0];a.innerText=`${a.innerText} (${td.children[1].children[0].title})`;}});
});
if ($('body').css('color')==='rgb(248, 248, 248)') $('style.d').remove();
});
</script>
<style class="d">
#page-container{background:#FFFDF0!important;}
body{background:#FFF8E8!important;}
.table.striped tr:nth-child(even){background:#FFF8E8;}
#problem-table tr:hover,#users-table tr:hover{background:#FFF0D0!important;}
.comment-display{background:#FFFFFF!important;}
.submission-row:hover{background:#FFF8E8!important;}
pre{background:#FFF8E8!important;}
</style>
<style>
#problem-table td.p,.fa-check+.pi-name+.pi-value{color:#0000!important;} // hide point value
</style>
<script>
List of features:
- Slightly yellow background to make an image's white background more visible, e.g. vmss7wc16c6p3.
- Hides point value.
- Highlights trailing whitespace, e.g. dmpg15b3.
- If you go to
/contest/<ongoing contest>/ranking/and click on the ongoing contest's name, then it removes finished contestants and adds the start time for ongoing contestants.
Fun facts
123*542=66666
O(n!) = O((n/e)^n) by Stirling's approximation.
Ｇｏｏｄ ｆｏｎｔ。
I still play osu! (mostly the mania mode). I can also say that this map is just slightly more difficult than this map.
There was another person in my high school with my same name and grade.
Points become exponentially annoying after 3000p or 200pp.
DM::OJ doesn't support multithreading.
Programming path:
- Codecademy (was an unpleasant experience)
- Project Euler (started June 2014) (stuck at 144)
- WCIPEG (started Feb 2015)
- DMOJ + Olympiads (started ~April 2015)
(Olympiads teacher)
Some of my submissions
Good submission to DMPG '15 S3 - Zen Garden (I wrote a program to do this).
Having the fastest solution written in Python
Some of other people's submissions
Second best comment (problem) (I can't remember that Thornhill banner anymore)
Longer compilation error (problem)
Unusual problem pages
Unusual facts about DM::OJ
dmoj has two chats: ancient dmoj chat and Slack (in the footer)
dmoj has an editorial page that is very hard to find. I think this is the only page with a link to it.
global_smurf's password is brucedontputmeintothepassword (why, kobortor?) (someone changed it for some reason) :( (I think r3mark changed it)
Unusual pages on the internet
Loop. (doesn't work anymore) :(
time.is isup.me repl.it
Markdown to visual. (Note: this website's markdown can parse LaTeX)
Math
$\frac d{dx}f(x)^{g(x)}$
Solve this problem to prove that you are okay at math:
Get all solutions satisfying these constraints.
Interesting problems (kind of outdated)
1000 testcases. (this problem should have used an input format similar to this problem)
Underrated Problems
(to 12p, but test cases are short so whatever) CCC '05 - Bananas
(to 7p) CCC '15 - Wait Time
(to 10p) COCI '14 Contest 7 #2 Kriza
(to 5p) CCC '02 - AmeriCanadian
(to 12p) ECOO '13 R1 P4 - Coupon Day
(to 12p) UTS Open '15 #2 - Secret Code
(to 30p) Free Desserts
(to 25p) IOI '17 P2 - Wiring
(to 40p) IOI '17 P3 - Toy Train
(to 15p) Kickstart '17 RA PA - Square Counting
Overrated Problems
(to 10p) CCC '13 - Chances of Winning
(to 7p) CCC '07 - Friends
(to 12p) Tree Cutting
(to 7p) P4 - HEIGHT
(to 35p) Terminus Est
Unreasonably Annoying Problems
More German Nouns
CCC '06 - Tin Can Telephone
DMPG '15 S2 - MMORPG
Sword Art Online Judge 2
Rotations in 3 Dimensions
ECOO '16 R2 P4 - Hop, Skip and Jump
Weird Problems
Polynomial Time Subset Sum
COCI '14 Contest 6 #6 WTF
Mackenzie New Year's Challenge P4 - Abdoof (possible in Turing)
Interesting problems (again)
Underrated Problems
(to 7p) DWITE '11 R3 #2 - Magical Ponds
(to 10p) CCC '01 S2 - Spirals (Exact Version)
(to 10p) COCI '17 Contest 4 #3 Automobil
(to 12p) DWITE '08 R5 #4 - Wiring the Server Room
(to 10p) Santa's Journey
(to 15p) ECOO '15 R3 P2 - Tiling Trouble
(to 17p) BinaryBomb
(to 12p) DWITE '07 R4 #5 - It all adds up (and it's a harder version of this)
(to 15p) DMOPC '17 Contest 3 P4 - Solitaire Logic
(to 17p) DMPG '17 S4 - Artillery Battery
(to 20p) ECOO '16 R3 P4 - Cuthbert's Calculator
(to 25p) Hanoi Heuristics
Overrated Problems
(to 3p) ECOO '18 R1 P1 - Willow's Wild Ride
(to 3p) COCI '08 Contest 3 #1 Pet
(to 3p) COCI '09 Contest 1 #2 Domino (reason: this is 3p)
(to 3p) DWITE '08 R5 #1 - Baby Diff
(to 3p) DWITE '10 R3 #2 - Unit rectangles (and it's a copy of this)
(to 3p) DWITE '08 R5 #2 - Kill Dash Nine
(to 3p) DWITE '11 R2 #1 - Wandering Billy
(to 5p) XOR Sum
(to 15p) JOI '13 - Watching
(to 4p) DWITE '08 R4 #1 - Four player Pong with no players
(to 4p) ICPC ECNA 2016 C - The Key to Cryptography
(to 4p) Summer Institute '17 Contest 1 P7 - Grand Theft Otto
(to 3p) Summer Institute '17 Contest 1 P10 - Trading Cards
(to 5p) CTU Open Contest 2018 - Horsemeet
(to 7p) CCO '96 P4 - Where's Waldorf?
(to 10p) DWITE '10 R5 #5 - Cube World
(to 10p) CCO '08 P5 - Candy
(to 10p) CCO '96 P3 - Quadtrees
(to 12p) COCI '18 Contest 3 #4 NLO
Unreasonably Annoying Problems
DWITE '07 R1 #3 - Where's my QWERTY?
ECOO '12 R1 P2 - Decoding DNA
DWITE '07 R4 #3 - Don't follow my links
COCI '08 Contest 5 #3 Jagoda
Sketchy Problems
DWITE '07 R1 #5 - Velociraptor Maze
ECOO '19 R1 P3 - Side Scrolling Simulator
DWITE '08 R5 #5 - Nash in Traffic
Things to do
Solve this problem in Turing.
Solve this problem in linear time.
Polynomial time subset sum (ancient dmoj history)
/\ | |
/ \ _ _| |__ _ __ ___ _ _
/ /\ \| | | | '_ \| '__/ _ \ | | |
/ ____ \ |_| | |_) | | | __/ |_| |
/_/ \_\__,_|_.__/|_| \___|\__, |
_ _ __/ |
/\ | | | | |___/
/ \ | |___| |_ ___ _ __
/ /\ \ | / __| __/ _ \| '_ \
/ ____ \| \__ \ || (_) | | | |
/_/ \_\_|___/\__\___/|_| |_|
10000 points
_., ,. ___.._ , /'|....._ |
| ,-' |'' / | \ `-|-/. _'-. _,....
,/''''''''.'/...\../= ,_|_.-.,.,- ,,,-' '
,' _\.|/+ |___, ---+-=-.--'. '''
,. -'_ '''''' =''.+-'|'`.|'\||,,'/
,' __...|...'`-.. .--'' . \ \. |+.|',==._,.._
.' _ `.......| \ .`'',+''++''-+ `\
| .' ||.|....| . | \|_,'' || | '
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_.,\. ., | \|||/'|.., + | | | || \
' .' ` ' , |||../,''-. |\ | | | || '
Fatal | '. / | ||'./,|.|-| |\ | | | ||
Eagle | `._|_ | ||.||+\.|.'.+' | | | ||
'. ' _,'_ -. ||.`\|..'' _| | | | ||
-/ ' ' / ||.|.'`-.,- | | | | || ,/
|/__ | | ||.|.|'-| | | | | ||-.'
_.-'' . | | ||.|.|..| | | | | _|| ,...
_,' \`+ \ - |..|.|..| | |__..,--+''_||_`.
-. '.__./|..|.''-|.,-+'''|__..,--''' || |
''/' ||.|.''-+.,-+'''| | | || |
/ ||.|.|..| | | | | || July 4, 2015
| ||.|.|..| | | | | || WA algorithm
||.|.|..| | | | | ||
||.|.|..| | | | | || I guess this
||.|.|..| | | | | || date is okay
Subset Sum Algorithm(Problem and the Github repository have been taken down)
Note: the first AC became WA because FatalEagle rejudged and made it easy for everyone else