to yours, and maybe it will help you to improve. ### Problem A. Turtle and
Good Strings #### My, ### Problem A. Turtle and Good Strings #### My approach during contest
(terrible way), ### Problem B. Turtle and Piggy Are Playing a Game 2 #### My approach during
contest (terrible way
→ Pay attention
→ Streams
→ Top rated
| # | User | Rating |
|---|---|---|
| 1 | Benq | 3792 |
| 2 | VivaciousAubergine | 3647 |
| 3 | Kevin114514 | 3611 |
| 4 | jiangly | 3583 |
| 5 | strapple | 3515 |
| 6 | tourist | 3470 |
| 7 | Radewoosh | 3415 |
| 8 | Um_nik | 3376 |
| 9 | maroonrk | 3361 |
| 10 | XVIII | 3345 |
→ Top contributors
| # | User | Contrib. |
|---|---|---|
| 1 | Qingyu | 162 |
| 2 | adamant | 148 |
| 3 | Um_nik | 145 |
| 4 | Dominater069 | 143 |
| 5 | errorgorn | 141 |
| 6 | cry | 138 |
| 7 | Proof_by_QED | 135 |
| 7 | YuukiS | 135 |
| 9 | chromate00 | 134 |
| 10 | soullless | 132 |
→ Find user
→ Recent actions
You can use several words in query to find by all of them at the same time. In addition, if you are lucky search understands word forms and some synonyms. It supports search by title and author. Examples:
305— search for 305, most probably it will find blogs about the Round 305andrew stankevich contests— search for words "andrew", "stankevich" and "contests" at the same timeuser:mikemirzayanov title:testlib— search containing "testlib" in title by MikeMirzayanov"vk cup"— use quotes to find phrase as istitle:educational— search in title
Results
1.
turtle
Last visit:
9 years ago
Registered:
13 years ago
2.
I stuggled with A and B in the last div 2, and how YOU can learn from it (CF 968 Div. 2) I noticed that sometimes I do some horrible things while solving easy problems. If you struggled with the first $2$ problems from the previous round, you might also have made some huge mistakes that should not happen.
**The point of this blog:** I will show you my terrible ways of approaching each of these problems and you will be able to see all of the stupid things that I did. Then I will show you the proper way to approach the tasks, and then you can think which approach is more similar to yours, and maybe it will help you to improve.
### Problem A. Turtle and Good Strings
#### My approach during contest (terrible way)
- I open the statement, incorrectly rephrase it: **you are given a string, you should divide it into several substrings, so in each substring the first and the last letters are different**
- I think of a dp solution, then I sloppily prove that I should take no more than $2$ substrings. I submit my [non-dp solution](https://mirror.codeforces.com/contest/2003/submi...
3.
How I reached GM using Generative Functions Hello, Codeforces!
In this blog, having thought of nothing better, I want to tell you a story.
A story about how little Chmyaaax, even before school, was forbidden to play computer games. About how, driven by a great desire to play tanks, he started making them in Scratch. About how he moved on from Scratch to Robot, and then to Turtle. From Turtle to Pascal. About how, at the age of 10, he was introduced to competitive programming. About how, after two failed Div3 contests, he quit for two years. About how, during that time, he passionately learned C++ so he could continue making computer games (which he still wasn’t allowed to play).
About how he later returned, motivated by money (the story about NEAR, where you had to reach 1600 to earn cash) (to then buy a second phone and play Brawl Stars). About how, after failing, he abandoned it again and went into commercial programming (making games). And then he came back to the sacred world, failing every TST the year before l...
moved on from Scratch to Robot, and then to Turtle. From Turtle to Pascal.
About how, at the age of 10, on from Scratch to Robot, and then to Turtle. From Turtle to Pascal. About
how, at the age of 10, he
4.
My solution to 2003F — Turtle and Three Sequences _I know this round is from like 2-3 months ago but screw that, let's dig it up because I just solved it recently. Also I cannot see any people who are doing the same thing as me._
## 1) The problem statement:
Problem link: [2003F — Turtle and Three Sequences](https://mirror.codeforces.com/contest/2003/problem/F)
Given two positive integers $n$, $m$ ($n \geq m$), and three sequences $a$, $b$, $c$ of size $n$. Find a sequence of length $m$ $p_1, p_2, ..., p_m$, such that $p_1 < p_2 < ... < p_m$, and $a_{p_1} \leq a_{p_2} \leq ... \leq a_{p_m}$, and $b_{p_i} \neq b_{p_j}$, $\forall i \neq j$.
Constraint:
- $n \leq 3000$, $m \leq 5$.
- $1 \leq a_i, b_i \leq n$, $1 \leq c_i \leq 10^4$.
- Time Limit: 3 seconds.
You can read the intended solution in this link: [Editorial](https://mirror.codeforces.com/blog/entry/132953).
<spoiler summary = "Spoiler:">
The intended solution uses randomization, which is very short, fast, cool and will definitely get you a lot of women in ...
My solution to 2003F — Turtle and Three Sequences, problem statement: Problem link: [2003F — Turtle and Three
Sequences](https://mirror.codeforces.com, Problem link: [2003F — Turtle and Three
Sequences](https://mirror.codeforces.com/contest/2003
5.
mBIT 2025 Editorial Thank you to everyone who competed in mBIT 2025! It was a record breaking year for us with 84 in-person participants and 135 online participants. We hoped you guys enjoyed it as much as we did.
We tried hard to make the problems fun and interesting for as wide of a skill gap as possible. In fact, this year's competition had an in-person team of middle schoolers that was unfamiliar with for loops, and an online team with all three participants in the top 15 in the world in codeforces. We are glad to contribute to all niches of the computer science community: beginner and advanced, local and global. Thank you all for your enthusiasm.
Congratulations to the winners:
**Online Advanced:**
- 1st place — HoMaMaOvo — Masaki Nishimoto, Riku Kawasaki, Yui Hosaka
- 2nd place — mathforcesbox — Brian Xue, Bing-Dong Liu, Alex Chen
- 3rd place — bluepuppygreenturtle — Rain Jiang, Kai Jiang
**Online Intermediate:**
- 1st place — NULP Lega...
Aak is the mayan word for turtle , Note everything that the limerick references: turtle, python, The problem is loosely about the Python turtle module. , The references to turtle, python, program, pen, and the example, The input are instructions for a python turtle to create drawings of a mayan
numeral. You have to
6.
Codeforces Round 968 Video Editorial (with Hints) (ABCD1D2E1E2) [Full video](https://youtu.be/9RMg-xKznTw)
[problem:2003A]
<spoiler summary="Hint 1">
Solve with $K=2$ only.
</spoiler>
My submission — [submission:278058173]
<spoiler summary="Video Editorial">
<iframe width="853" height="480" src="https://www.youtube.com/embed/9RMg-xKznTw?start=245" title="Codeforces Round 968 Solution Discussion | ABCD1D2E1E2" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
</spoiler>
[problem:2003B]
<spoiler summary="Hint 1">
Turtle wants to maximise the remaining value, so he should try to remove the smallest values.
Similarly Piggy wants to minimise the remaining value, so he should try to remove the largest values.
</spoiler>
My submission — [submission:278054761]
<spoiler summary="Video Editorial">
<iframe width="853" height="480" src="...
Turtle wants to maximise the remaining value, so he should try to
Tutorial of Codeforces Round 968 (Div. 2)
7.
Codeforces Beta Round #96: editorial <h3><a href="http://mirror.codeforces.com/contest/133/problem/A">A. HQ9+</a></h3> <p>The problem described <a href="http://progopedia.com/language/hq9-plus/">HQ9+</a> programming language and asked whether the given program will print anything. Given the extraordinary simplicity of the language, it was enough to check whether the program contains at least one of the characters H, Q and 9.</p> [cut] <h3><a href="http://mirror.codeforces.com/contest/133/problem/B">B. Unary</a></h3> <p>A lovely language <a href="http://progopedia.com/language/brainfuck/">Brainfuck</a> has dialects for literally every occasion; I guess one could write a whole round about it (not Unknown Language Round, of course, it's too well-known for it), but this time I used it in one problem only.</p> <p>The solution is quite simple: all you have to do is to follow the described procedure of transforming code from Brainfuck to Unary. If your language has built-in long arithmetics, the solution is straightforward: replace characte...
E. Logo Turtle <http://mirror.codeforces.com/contest/133/problem/E>
This was the
, from the list, all facing directions of the turtle and all quantities of
changes which have the same, href="http://mirror.codeforces.com/contest/133/problem/E">E. Logo Turtle
This was the only
Tutorial of Codeforces Beta Round 96 (Div. 1)
Tutorial of Codeforces Beta Round 96 (Div. 2)
8.
Invitation to CodeChef August Cook-Off 2016 Hello CodeForces Community!
I’d like to invite you to the [CodeChef August Cook-Off](https://www.codechef.com/COOK73). As usual, the CookOff will be on the second last Sunday of the month.
Joining me on the problem setting panel are:
- Problem Setter: [user:alei,2016-08-20] (Alei Reyes)
- Problem Tester: [user:kingofnumbers,2016-08-20] ( Hasan Jaddouh)
- Editorialist: [user:PraveenDhinwa,2016-08-20] (Praveen Dhinwa)
- Russian Translator: [user:Cherrytree,2016-08-20] (Sergey Kulik)
- Mandarin Translator: [user:huzecong,2016-08-20] (Hu Zecong)
- Vietnamese Translator: VNOI Team
- Contest Admin and Language Verifier: [user:PraveenDhinwa,2016-08-20] (Praveen Dhinwa)
Especial thanks go to [user:Miyukine,2016-08-20] for his appreciation of the problem-set before I send it to CodeChef, he have a good taste in programming contests so I'm glad he found the problems interesting.
The contest theme is based on Lewis Carroll's book Alice's Adventures in Wonderland.
Problem...
The problem is equivalent to the number of dyck paths that touches, summary="Mock Turtle"> The problem is equivalent to the number of dyck paths
that touches the diagonal
9.
Editorial for Turtle and GCD (My first problem) Recently I wrote my very first problem (that was $>$ D2A and not just a standard application of an algorithm) that I both wrote and solved myself.
Link: https://mirror.codeforces.com/gym/104669/problem/L
<spoiler summary = "Editorial">
Let $R$ be the sum of all the elements.
Denote the sum of the first set to be $s1$ and the sum of the second set to be $s2$.
Notice that the gcd has to be a factor of $R$ because if $\text{gcd} | s1$ and $\text{gcd} | s2$ then $\text{gcd} | (s1 + s2)$.
So we can check every factor of $R$, see if it possible achieve this factor as the $\text{gcd}$, and then take the max factor that works.
A factor $f$ works if there is a subset $s$, $|s| < b$ that adds up a multiple of $f$ because the sum of the numbers from $a$ to $a + b - 1$ not in $s$ will also be divisible by the $f$.
We need to find some way to optimize knapsack dp using the fact that the numbers are consecutive.
Considering fixing the size of the subset to be $s$.
Claim: There exists ...
Editorial for Turtle and GCD (My first problem)
10.
2023-The 5th Turing Cup Tournament **Turing Cup Tournament**
The Turing Cup is an invitational competition that is organized by one of the most successful informatics competition teams in China, the XinYouDui and partner with X-Camp Academy.
**Registration time:** April 7th — May 13th 12:30 PM（BJT）/ May 12th 9:00 PM PDT/ May 13th 00:30 AM EDT
**Registration method:** Click XinYouDui contest system directly for registration. So [register here while you can](https://contest.xinyoudui.com/recommend)! (It is recommended to use Chrome, Firefox browser)
**Registration requirements:** There are no age, level, or identity restrictions.
**Discord Link**: [Join the discord for Q&As and discussions](https://discord.gg/6SkkJ3f55p)!
These awesome problems and editorials are written, prepared, and tested by the X-Camp and XinYouDui Team, **including 4 Chinese national team members,**
[user:orzdevinwang,2023-05-12], [user:Rebelz,2023-05-12], [user:hehezhou,2023-05-12], [user:djq_cpp,2023-05-12], [user:unputdo...
(Turtle Beach Headset)
11.
Video Editorial for Codeforces Round 1078 Note: The text editorials will be provided by the authors of the round. This video tutorial acts as an additional resource for those who prefer video over text, not as a substitute for the text editorial.
Thanks to [user:Shayan,2026-02-08]
### [2194A — Lawn Mower](https://mirror.codeforces.com/contest/2194/problem/A)
<spoiler summary="Video">
<iframe width="800" height="450" src="https://www.youtube.com/embed/04mKlslyrwE?start=77" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></iframe>
</spoiler>
### [2194B — Offshores](https://mirror.codeforces.com/contest/2194/problem/B)
<spoiler summary="Video">
<iframe width="800" height="450" src="https://www.youtube.com/embed/04mKlslyrwE?start=478" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen></ifram...
### [2194E — The Turtle Strikes
Back](https://mirror.codeforces.com/contest/2194/problem/E)
12.
Congratulations to Sparky_Master_WCH1226 Dear [user:Sparky_Master_WCH1226,2022-04-19],
Congratulations for reaching <span class="user-red">Grandmaster</span> and gaining your brand new <span class="user-red">red</span> name <span class="rated-user user-red">Sparky_Master_WCH1226</span>!!!
We have been so used to seeing <span class="rated-user user-orange">Sparky_Master_WCH1226</span> ever since you became <span class="user-orange">Master</span> in [contest:1623], less than 24 hours after you reached <span class="user-violet">Candidate Master</span> in [contest:1622].
While red is a nice colour, it is quite sorrowful to say goodbye to the familiar <span class="rated-user user-orange">Sparky_Master_WCH1226</span>. Goodbye, goodbye, goodbye, we will remember <span class="rated-user user-orange">Sparky_Master_WCH1226</span> forever... Unless, of course, if it occurs that our beloved (or shall I say, much loathed?) <span class="rated-user user-red">Sparky_Master_WCH1226</span> decides to go back to the familiar <span clas...
turtle speed
13.
masterpiece.txt Bee Movie Script
According to all known laws
of aviation,
there is no way a bee
should be able to fly.
Its wings are too small to get
its fat little body off the ground.
The bee, of course, flies anyway
because bees don't care
what humans think is impossible.
Yellow, black. Yellow, black.
Yellow, black. Yellow, black.
Ooh, black and yellow!
Let's shake it up a little.
Barry! Breakfast is ready!
Ooming!
Hang on a second.
Hello?
- Barry?
- Adam?
- Oan you believe this is happening?
- I can't. I'll pick you up.
Looking sharp.
Use the stairs. Your father
paid good money for those.
Sorry. I'm excited.
Here's the graduate.
We're very proud of you, son.
A perfect report card, all B's.
Very proud.
Ma! I got a thing going here.
- You got lint on your fuzz.
- Ow! That's me!
- Wave to us! We'll be in row 118,000.
- Bye!
Ba...
Yes! I'm right off the Turtle Pond!
14.
Contest Day#1 Editorial [contest:364982]
<spoiler summary="A. Fafa and his Company">
~~~~~
#include<bits/stdc++.h>
using namespace std;
int main(){
int n, cnt = 0;
cin >> n;
for(int i=1; i<n; i++){
if((n-i)%i == 0) cnt++;
}
cout << cnt;
}
~~~~~
</spoiler>
<spoiler summary="B. Simple XML">
~~~~~
#include<bits/stdc++.h>
using namespace std;
int main(){
string in;
cin >> in;
int l=in.length();
vector<string> v;
for(int i=0; i<l-3; i++){
if(in[i+1]=='/'){
v.push_back(in.substr(i,4));
i+=3;
}else{
v.push_back(in.substr(i,3));
i+=2;
}
}
int s = v.size(), sp = 0;
for(int i=0; i<s; i++){
if(v[i][1]=='/') sp--;
for(int j=0;j<sp*2; j++){
cout << ' ';
}
cout << v[i] << '\n';
if(v[i][1]!='/'){
sp++;
}
}
}
~~~~~
</spoiler>
<spoiler summary="C. Good String">
~~~~~
#include<bits/stdc++.h>
using namespace std;
int main(){
int t;
cin>>t;
while(t--){
string s;
cin >> s;...
15.
Programming contests and programming languages (in problems) A couple of days ago I wondered how many authors (except for me) write problems about programming languages. I was hoping to be not alone in my passion to this topic; but the reality exceeded all expectations.
Of course, problems which feature programming languages are much scarcer than ones about computers, processors, microchips, parallel computing, databases and other IT things, but still
much more frequent than ones about, say, dragons :-)
#### 1. TopCoder ####
The early years of TopCoder presented the participants with several programming-languages-featuring problems.
[cut]
Most of them (7/9) are pretty similar: given the source code written in C- or Pascal-like language,
analyze it and report the result.
| Problem | Task |
|--|--|
| [QuiningTopCoder](http://community.topcoder.com/stat?c=problem_statement&pm=1764) | Write an interpreter for Unefunge |
| [ScriptLanguage](http://community.topcoder.com/stat?c=problem_statement&pm=1956) | Given source code in Visual...
| |
[TurtleGraphics](http://community.topcoder.com/stat?c=problem_statement&pm=6877)
|Turtle graphics in, ://community.topcoder.com/stat?c=problem_statement&pm=6877) | Turtle graphics
in 3D |
16.
Problem C topic list Tell the topics which you think are very commonly used in rated for Div 2 C problems and if possible share a problem link.
<spoiler summary="greedy">
[Chamo and Mocha's Array 1975C](https://mirror.codeforces.com/contest/1975/problem/C)
<br>
[Permutation Counting 1972C](https://mirror.codeforces.com/contest/1972/problem/C)
<br>
[Everything Nim 1966C](https://mirror.codeforces.com/contest/1966/problem/C)
<br>
[Messenger in MAC 1935C](https://mirror.codeforces.com/contest/1935/problem/C)
<br>
[Lexicographically Largest 1930C](https://mirror.codeforces.com/contest/1930/problem/C)
</spoiler>
<spoiler summary="binary-search">
[Job Interview 1976C](https://mirror.codeforces.com/contest/1976/problem/C)
<br>
[Tree Cutting 1946C](https://mirror.codeforces.com/contest/1946/problem/C)
</spoiler>
<spoiler summary="constructive-algorithms">
[Turtle and an Incomplete Sequence 1981C](https://mirror.codeforces.com/contest/1981/problem/C)
<br>
[Cat, Fox and Double Maximum 1973C](https://mirror.codeforces.com/contest/1973/problem/C)
<br>
...
[Turtle and an Incomplete Sequence 1981C](https, -algorithms"> [Turtle and an Incomplete Sequence
1981C](https://mirror.codeforces.com/contest/1981/problem
17.
[Video]: The anti Diagonal trick for Grid DP ft. CF2194E Everyone knows the classical Dynamic Programming problem of finding the max profit path in a grid. But can you quickly find out the maximum profit when I change an arbitrary cell's value? I discuss an anti diagonal trick that can be used to solve such problems. This idea appeared in a recent Div 2 contest, [E. The Turtle Strikes Back](https://mirror.codeforces.com/problemset/problem/2194/E)
Video https://youtu.be/ms8douXze4E
contest, [E. The Turtle Strikes
Back](https://mirror.codeforces.com/problemset/problem/2194/E)
18.
Help with Game Theory Problem POJ 1704 Hello there
I've been trying to figure out how to turn this [problem](http://poj.org/problem?id=1704) into a game of nim but with no luck
if anyone could help it would be really appreciated :D
extra question : i've been thinking the game of turning turtles for a while and the logic behind it
it's a game where we have a row of turtles some on their backs some on their legs ... in each move you can turn a turtle that's on its back and put it on it's legs and u can optionally turn a turtle with position on it's left from any state to the opposite state ... he who can't make anymore moves loses ... any help with that would be really appreciated :D
move you can turn a turtle that's on its back and put it on it's legs and u
can optionally turn a, you can turn a turtle that's on its back and put it on it's legs and u can
optionally turn aturtle
Codeforces (c) Copyright 2010-2026 Mike Mirzayanov
The only programming contests Web 2.0 platform
Server time: May/17/2026 12:23:52 (g1).
Desktop version, switch to mobile version.
Supported by
