**2573 problems solved**

**Rank by points:**#4

**Total points:**936

**46 contests written**

**Rank by rating:**#5

**Rating:**2980

**Volatility:**188

**Min. rating:**1550

**Max rating:**2988

**From**
Pierre Elliott Trudeau H.S., Canadian Computing Olympiad, University of Waterloo, Olympiads Computing Competition

#### About

##### List of broken problems

This page lists all IEs, so I don't need to list those problems here

**bold**: if this is fixed, then the problem will be much easier to solve

- (nothing yet)

Easiest problems that I didn't solve yet: (problems modified after 2020-05-29 don't count)

Represented Dmojistan at IOI 2017.

Fun fact: The DMOJ logo isn't symmetrical. This is obvious in the logo below (and in this problem). This is not obvious when the logo is tiny (like the logo in the top-right of every DMOJ page).

```
#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();
```

#### 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 (stuck at 144)
- WCIPEG
- DMOJ + Olympiads

(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 a neglected page (now deleted).

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

HTML to markdown. (Note: poor quality converter)

Markdown to visual. (Note: this website's markdown can parse LaTeX)

#### Math

$$\displaystyle \frac d{dx}f(x)^{g(x)}$$

$\frac d{dx}f(x)^{g(x)}$

~\frac d{dx}f(x)^{g(x)}~

Solve this problem to prove that you are okay at math:

Get all solutions satisfying these constraints.

~a,b,c,d\in\mathbb{C}~

~d\notin\mathbb{R}~

~\begin{cases}b\times c\times d=b+c+d\\c\times d\times a=c+d+a\\d\times a\times b=d+a+b \\a\times b\times c=a+b+c\end{cases}~

#### 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 12p) Rotations in 3 Dimensions

(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 3p) Hailstone Numbers

(to 10p) System(0);

(to 25p) Matrix Determinant

(to 5p) Encode

(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 5p) DWITE '11 R1 #1 - Arab-lish Numbers

(to 7p) DWITE '11 R3 #2 - Magical Ponds

(to 7p) DWITE '10 R2 #4 - Fractions to Decimal

(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 30p, but test cases are broken and weak) ICHB Selection Contest '17 Problem 1 - Airship Fights

(to 15p) DMOPC '17 Contest 3 P4 - Solitaire Logic

(to 15p) 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) DWITE '11 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
_., ,. ___.._ , /'|....._ |
| ,-' |'' / | \ `-|-/. _'-. _,....
,/''''''''.'/...\../= ,_|_.-.,.,- ,,,-' '
,' _\.|/+ |___, ---+-=-.--'. '''
,. -'_ '''''' =''.+-'|'`.|'\||,,'/
,' __...|...'`-.. .--'' . \ \. |+.|',==._,.._
.' _ `.......| \ .`'',+''++''-+ `\
| .' ||.|....| . | \|_,'' || | '
| ||.|.|..| | | |_,'| ,'|___'
.-----,-- ||.|.|..| | |' -' | ' || --.
'''''`\ _.-' '-. ||..,_-...._| | | | |+' '\
_.,\. ., | \|||/'|.., + | | | || \
' .' ` ' , |||../,''-. |\ | | | || '
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