**307 problems solved**

**Rank by points:**#254

**Total points:**462

**2 contests written**

**Rank by rating:**#738

**Rating:**1445

**Volatility:**302

**Min. rating:**1397

**Max rating:**1445

#### About

random person#5620 | anilist | github

sacrificing non existent math skills for cp since September 18 2020 (start of grade 10)

python/c++ (trying to transition)

i use cp editor and its op asf

i just found out about debuggers are they're also op asf

still use replit sometimes (mainly for python) but its nowhere near as good

file submission is TRASH

**1 dmoj question a day, keeps my incompetence away** (not really)

i encourage you to come join this cult

tfw ur diary is on ur profile page of an online judge

i wonder if i'll run out of space some day

**Milestones** cuz why not:

10/03/2020 - 69 problems solved

10/20/2020 - 100 problems solved

11/26/2020 - 300 points

12/17/2020 -

12/30/2020 -

01/10/2021 -

01/19/2021 -

**Target for CCC 2021**: 40/75 (aim high, hit low amirite)

**Random**

best sub if you are reading this please dont make a point in beating my submission it is my only achievement in life please please please

#### Problems Solved Log

most problems below 10 points are not documented

for hard questions, I often write extensive explanations in my code if you're interested (i usually don't write them for python submissions though)

currently stuck on:

1/21/2021

surfing

1/20/2021

Inaho

1/19/2021

did some random easy problems to ~~westbrook~~ pad my stats

WC '18 Contest 4 S1 - World of StarCraft (10)

1/18/2021

Tree Tasks (10)

im stupid for needing help fml. ended up calculating eccentricity for all nodes kekw

**(spoilers)**

writing down this approach cuz its op asf

dfs from any node to the farthest node u

dfs from u to farthest node v. reroot the tree at node u at the same time

diameter is distance between u and v as we all know

now comes big brain strat for finding radius:

we can traverse each node on the diameter by starting at node v and calling parent(v), until we reach u

this works because every node only has one parent. the root is at u so u is definitely an ancestor of v

so just traverse like so and take radius = min(radius, max(<length-bottom-up-so-far>, diameter length - <length-bottom-up-so-far>) for every node on the diameter

1/17/2021

Intervals' nlogn solution is fking hard to understand man...spent like the entire day trying and now i have no time for schoolwork.

if anyone ever comes up with a clear explanation im all ears

edit: understand a lot better now because of random translated japanese blogs lmao

1/16/2021

DMPG '16 S5 - Pizza Bag (12)

Intervals (6/20) i finish this tmr dw :D

1/15/2021

Tower (20)

really interesting

1/14/2021

Subtree (20)

solved with help

1/13/2021

CCO '10 P2 - Tree Pruning (15)

IOI '01 P1 - Mobile Phones (10)

1/12/2021

CCO '14 P3 - Werewolf (17)

tried debugging my transition for hours AND IT WAS THE FKING BASE CASE fml

1/11/2021

VM7WC '16 #4 Gold - Restoring Reputation (10)

DMOPC '15 Contest 5 P5 - World Line Convergence (15)

1/10/2021

A Fundraising Problem (12)

solved with help. underrated

1/9/2021

did some ez problems also known as slacked off

1/8/2021

COCI '20 Contest 2 #2 Odašiljači (7)

underrated

1/7/2021

did some ez questions

1/6/2021

got stuck on a fundraising problem and failed :(

1/5/2021

A Digit Problem (15)

DMOPC '14 Contest 2 P5 - Sawmill Scheme (15)

COCI '07 Contest 3 #5 Cudak (15)

accidentally becoming decent at digit dp somehow

1/4/2021

Art Academy VII: A Mysterious Object (12)

^ underrated

Baltic OI '13 P2 - Palindrome-Free Numbers (15)

not enough time to do compsci dammit

1/3/2021

Christmas Cards (15)

DMOPC '14 Contest 3 P6 - Not Enough Time! (15)

1/2/2021

Art Academy V: Ruin (12)

IOI '09 P4 - Raisins (15)

yo i remember seeing this and being so confused a few months ago but i acc solved this yoooooooo

Binary Indexed Tree Test (10)

wasted hour(s) trying to use segment tree to do binary indexed tree test (???) lovely

CCO '15 P2 - Artskjid (15)

CCO '14 P1 - Troyangles (10)

DWITE '12 R5 #3 - Triangle Count (7)

1/1/2021

CCC '07 S5 - Bowling for Numbers (10)

CCC '08 S5 - Nukit (10)

Simon and Marcy (10)

IOI '00 P1 - Palindrome (10)

10 point dp problems are like the sweet spot for me

12/31/2020

DMOPC '14 Contest 3 P5 - Not Enough Servers! (20)

COCI '08 Contest 2 #5 Setnja (7)

looked solution cuz ive been stuck on it for 6 months now

Back From Summer '19 P2: Straying From God's Light (7)

came up with a solution way more intuitive than editorial :)

PalinDrone (12)

lame

12/30/2020

CCC '14 S3 - The Geneva Confection (7)

Connected Components (10)

Directed Acyclic Graph (10)

Counting Paths (10)

Trees (10)

Travelling Salesmen (10)

Shortest Path (7)

Cable TV (7)

i actually need sleep. slept right through the CF round...im never gonna climb out of gray am i

12/29/2020

Summer Institute '17 Contest 1 P5 - Crazy Math (15)

TLE '15 P4 - Olympiads Homework (12)

Recurrence Solver (15)

Fibonacci Sequence (Harder) (20)

12/28/2020

Flowers (15)

wanted to use a BIT and then decided it wasnt possible (?????) and implemented a segment tree recursively instead (which took me hours kekw)

Grid 2 (17)

12/27/2020

Victor Makes Bank (17)

used editorial, didnt use brain (edit: understand now)

A Coin Problem (12)

12/26/2020

Coin Change (10)

12/25/2020

Walk (15)

very, very cool. i hope for a visualization somewhere. edit: kinda similar to floyd warshall idea so ig it makes sense

12/24/2020

Digit Sum (15)

A Romantic Dinner (15)

12/23/2020

Permutation (15)

also did forming quiz teams from another oj

12/22/2020

Counting Cycles (10)

Hurontario (10)

Roadrollification (10)

12/21/2020

Grouping (15)

looked editorial but shouldve been able to solve D:

12/20/2020

Sushi (12)

A little bit proud that i actually solved this

12/19/2020

did some random ez problems (?)

12/18/2020

Slimes (12)

quite reminiscent of combining riceballs (but much easier than that)

Candies (12)

12/17/2020

Matching (12)

ECOO '16 R3 P3 - CamelCase (10)

COCI '06 Contest 1 #5 Bond (10)

solved with help

12/16/2020

Stones (10)

Coins (10)

Grid 1 (10)

12/15/2020

LCS (7)

Longest Common Subsequence (7)

Deque (10)

A Game (10)

12/14/2020

Poutine (10)

Floyd Warshall go brrrr

Disjoint Set Test (10)

my eyes hurt so bad right now i need to squint why am i typing this i need sleep i wake 9 tmr somehow ok bye

12/13/2020

DMPG '15 B4 - Maximum Product (7)

12/12/2020

Independent Set (12)

Longest Increasing Subsequence (7)

Longest Increasing Subsequence (7)

Mock CCO '18 Contest 3 Problem 4 - Roger Solves A Classic Rage Tree Problem (10)

12/11/2020

COCI '08 Contest 3 #5 BST (20)

COCI '06 Contest 3 #5 Bicikli (15)

12/10/2020

Gates (10)

12/05/2020

Back To School '18: Function Maximization (25)

DMOPC '15 Contest 1 P6 - Lelei and Contest (17)

12/02/2020 (12:48 at night so)

2-Dimensional Range Minimum Query (17)

basically, this is one of the most useless and painful things ive ever done

11/30/2020

Checkerboard Summation (hard) (15)

UTS Open - Pogo (25)

Phenomenal Reviews (13/15) -> (15/15)

11/28/2020

Another Contest 3 Problem 4 - Range Updates and Range Queries (15)

Checkerboard Summation (Easy) (12)

gonna do the hard one tmr. i think perhaps like a 2d BIT or segtree or something

11/27/2020

DMPG '17 G2 - Holy Grail War (20)

**FROM NOW ON I WILL ONLY JOURNAL WHEN I SOLVE A QUESTION ON THE DAY...**

11/26/2020

Bananas (10)

11/23/2020

Segment Tree Test (15)

11/22/2020 (2 am 11/23)

COCI '07 Contest 3 #6 Redoks (17)

took me a good while (12+ hours prob), gave up debugging and read editorial at the end but i wasnt too far off i think.

11/21/2020

*failed*

tried COCI '07 Contest 3 #6 Redoks but obviously i tle :D

11/12/2020 - 11/20/2020

*failed*

my excuse is cimc (which i choked)

11/11/2020

Maze (10)

Can Shahir even get there?! (5)

Degrees of Separation (10)

Word Scrambler (7)

Switch (12)

kinda just chilled out today, did a couple ez graph theory ones and cheated a 12 pt

11/10/2020

*failed*

wait why is Poutine so hard...editorial is a lie theres no way naive bfs passes

funny part is when i found out it was too slow with python, i spent 1 hour redoing it in c++ and its even slower

**bruh**

11/9/2020

Swapping Seats (12)

11/1/2020 - 11/8/2020

*failed*

idk what happened either :D

10/31/2020

A Knightly Pursuit (12)

Knight Hop (7)

10/30/2020

Winning at Sports (12)

i think too ez for 12 pts, esp considering time limit. didnt even need to reuse table for each case

10/29/2020

Searching for Strings (10)

Compsci Club took this one up, otherwise i would never have gotten this by myself. also this Microwaving guy is so insane actually. python best language

anyways got fse/exams coming up gonna slow down with the compsci for a while

10/22/2020 --- 10/28/2020

*failed*

uh so basically comc happened so i gave up on compsci for a short while. well i guess i'll have to go back to math again soon cuz cimc

10/21/2020

Shop and Ship (15)

forgot to record this one...

10/20/2020

Pinball Ranking (15)

~ 6-7 articles and a couple yt videos later... i am finally enlightened. also now that i look at other solutions, i guess this was a pretty common approach actually. interesting nonetheless

100 problems solved. thank you to everyone who helped me along the way

10/19/2020

*failed*

i found an extremely simple and interesting solution to Pinball Ranking, but i dont fully understand it yet (after hours of trying xD) so i'll hold off on the submission until i do. the man actually replied to my email tho

10/18/2020

Pinball Ranking (5.25/15) :(

ok i rlly underestimated this. implementing BST not enough i guess. anyone gimme a hint pls?

10/17/2020

Trucking Troubles (12)

Longest Path (10)

10/16/2020

Animal farm (15)

wow that took a lot less time than i thought it would to actually solve the problem

Waterpark (10)

10/15/2020

*failed*

spent some time trying to understand animal farm. i'll continue this tmr

10/14/2020

Combining Riceballs (15)

FINALLY LETS GOOOOOOO!!!!

20 HOURS OF ENDLESS CONFUSION AND DEBUGGING I FINALLY GOT IT

i finally have one thing in life i can be proud of

10/13/2020

*failed*

worked on Combining Riceballs from 9 am to 1 am the next day. actually hard.

10/12/2020

DMOPC '20 October Contest {P1, P2, P3, P5 (15/100)}

Factor Solitaire (15)

wrote the dmopc today. so mad i didnt get partials for P4, i really dont know how. got partials for P5 tho, so i think i neither underperformed nor overperformed

factor solitaire is rlly free go do it

10/11/2020

Who is Taller (10)

Chances of Winning (12)

Substrings (15)

10/10/2020

Matrix Operation (10)

Cherrie Tree (12)

jk back to python

10/9/2020

Rank (10)

10/8/2020

Vacation (7)

Knapsack (7)

10/7/2020

List Minimum (4) (already done in python)

Triple Fat Ladies (5)

Rock Paper Scissors Fox (3)

A Minus B (3)

Quadrant Selection (3)

Deforestation (7) (already done in python)

Frog 1 (7)

List Minimum (Hard) (5)

Frog 2 (7)

only challenge was c++ syntax. and yes i might be converting to c++ now. goodbye python

10/6/2020

Convex Hull (15)

i dont think the editorial explained everything clearly. ended up not using a prio queue at all and still worked. oh and i repeated variable names which caused me to WA like 3 times i was actually so confused lmao

10/5/2020

*failed*

tried several different ways to reduce memory usage on Phenomenal Reviews, but i suspect python recursion stacks are just too huge. will come back after learning cpp

10/4/2020

Phenomenal Reviews (13/15)

i did read the editorial. im taking up too much memory, i think i'll try pruning and doing the first search at the same time tmr. (Edit: cant get under the memory limit. gg)

10/3/2020

Super Plumber (10)

i've been stuck on this one for a while now. very interesting approach, never done dp gt like this one before. learned a lot doing this one, definitely recommend

4 nations 1 secret (10)

was stuck on this one 10 months ago, came back to it randomly. not extremely challenging

69 problems solved btw

10/2/2020

Maximum Sum (7)

found a way to do it without recursion, while taking in input feelsgoodman

10/1/2020

AFK (12)

in reality wasnt that hard (everything is easy once you solve it xD). just note that passing in (x,y,cost) is worse compared to using another array to store cost for large test cases

Math 137 at Squirreloo (7)

one of the hardest easy 7 points ive ever done in terms of optimizing runtime. technically solved 1:09 am 10/2

9/30/2020

failed

made some progress on Super Plumber, got distracted by Maximum Sum. then got distracted by AFK. didnt finish any of them

btw how is maximum sum so hard. well not hard but MLE last case. i only have an input list and a memo array bruhhh

9/29/2020

Sheep and Coyotes (10)

ALWAYS REMEMBER TO USE DECIMAL MODULE WHEN DOING CALCULATIONS!!! PYTHON FLOATS ARE NOT ACCURATE! (thank you very much alexshao)

9/28/2020

Frank and Roads (10)

confusing question statement. in actuality a very trivial bfs implementation question that should really be worth 7 points max

9/27/2020

Neanderthal Numbers (10)

pretty easy took a little bit of thought was all

9/26/2020

Fibonacci Sequence (15)

thank you http://jeffe.cs.illinois.edu/teaching/algorithms/book/03-dynprog.pdf, very cool

Pyramid Message Scheme (10)

technically finished 9/27/2020 after midnight

9/25/2020

*Failed*

WHY IS SUPER PLUMBER SO HARD BRUH. tried recursion, realized halfway that might not ever go back to bottom left kekw. implemented a naive bfs but obv tle, mle

9/24/2020

*Failed* (technically i did Golf today at 12 am in the morning)

Tried Super Plumber, can probably do it with bfs but no idea how to tabulate, because each node potentially depends on each other

9/23/2020

Bridge Crossing (10) (Finally! Lesson learned: memoize the remaining part of the branch, and not anything related to before it)

Golf (10) (quite straightforward, took a long time bc was too lazy to trace recursion. TRACE IF STUCK NEXT TIME. also check memo first thing) p.s. technically solved 9/24/2020 around 12 am

9/22/2020

Mouse Journey (10) (this one pretty easy ngl) (tried bridge crossing, came extremely close but cant figure out memoization)

9/21/2020

π-day (10) (my first 10 point dp. made me think a bit. i think i did the reverse of the editorial solution still worked tho)

9/20/2020

*Failed* (tried "Setnja" and "Straying from God's light", gave up on both)

9/19/2020

Spreadsheet (10) (recursion with cycle detection, stupid bug slowed me down couple hours lmao)

9/18/2020

Crossing Field (10) (pretty straightforward bfs i think)

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