# IMe and DeepSeek analyzed 1600 Codeforces contests and 8000+ problems — some interesting patterns↵
↵
please check this result : https://ayushgirigoswami.github.io/codeforces_analysis_report/↵
↵
A few weeks ago I got curious about something most of us probably notice intuitively but rarely measure properly:↵
↵
* Is Codeforces getting harder over time?↵
* Which topics are becoming more common?↵
* Are some problems overrated or underrated?↵
* How different are Educational rounds from regular rounds?↵
↵
So I wrote a Python script that pulls contest/problem data from the CF API, analyzes ratings + tags, and generates interactive visualizations.↵
↵
### Report↵
↵
https://ayushgirigoswami.github.io/codeforces_analysis_report/↵
↵
### Source code↵
↵
https://github.com/Ayushgirigoswami↵
↵
---↵
↵
## Dataset↵
↵
The analysis includes:↵
↵
* 1600 contests↵
* 8354 rated problems↵
* Div.1 / Div.2 / Div.3 / Div.4 / Div.1+2↵
* 2011 → present↵
↵
Average problem rating across the dataset: **1793**↵
↵
---↵
↵
# Some interesting results↵
↵
## 1) Div.1+Div.2 rounds have the widest difficulty spread↵
↵
| Division | Avg Rating | Median | Std Dev |↵
| -------- | ---------- | ------ | ------- |↵
| Div.1 | 2358 | 2400 | 714 |↵
| Div.2 | 1630 | 1600 | 652 |↵
| Div.1+2 | 2096 | 2100 | 927 |↵
| Div.3 | 1429 | 1400 | 513 |↵
| Div.4 | 1213 | 1100 | 412 |↵
↵
Div.1+2 rounds have by far the largest standard deviation.↵
↵
Makes sense in hindsight: these rounds combine easy entry problems with very high-end G/H problems, so the spread becomes huge.↵
↵
Also interesting:↵
even Div.1 A problems average around **1537**, which is already harder than many Div.2 mid-problems.↵
↵
---↵
↵
## 2) Biggest difficulty jumps are usually B→C and C→D↵
↵
Average Div.2 ratings by position:↵
↵
* A ≈ 903↵
* B ≈ 1203↵
* C ≈ 1552↵
* D ≈ 1932↵
* E ≈ 2300↵
* F ≈ 2614↵
↵
The largest jumps are:↵
↵
* B → C : +349↵
* C → D : +380↵
↵
This matches what many contestants experience during contests:↵
B is often straightforward, while C/D is where actual problem solving starts becoming important.↵
↵
For Div.1+2 rounds, the jump near the end becomes even more extreme:↵
↵
* F ≈ 2697↵
* G ≈ 3102↵
* H ≈ 3160↵
↵
---↵
↵
## 3) Topic trends over time↵
↵
### Increasing frequency↵
↵
* greedy↵
* math↵
* constructive algorithms↵
* data structures↵
* binary search↵
* dp↵
* trees↵
* bitmasks↵
* interactive↵
↵
### Decreasing frequency↵
↵
* implementation↵
* geometry↵
↵
The increase in interactive problems during the last few years was especially noticeable.↵
↵
Geometry also appears much less frequently than older rounds.↵
↵
---↵
↵
## 4) Most common tags↵
↵
| Tag | Total |↵
| ----------------------- | ----- |↵
| greedy | 2885 |↵
| math | 2805 |↵
| implementation | 2407 |↵
| dp | 1980 |↵
| constructive algorithms | 1677 |↵
| brute force | 1644 |↵
| data structures | 1620 |↵
| binary search | 1022 |↵
↵
Some observations:↵
↵
* DP is disproportionately common in Div.1.↵
* Implementation dominates Div.2/3 but drops heavily in Div.1.↵
* Graph-related problems appear much more frequently than I expected.↵
↵
---↵
↵
## 5) Educational rounds vs regular rounds↵
↵
This part surprised me.↵
↵
| Type | Overall Avg | A | B | C | D | E | F |↵
| ----------- | ----------- | ---- | ---- | ---- | ---- | ---- | ---- |↵
| Educational | 1769 | 873 | 1118 | 1465 | 1842 | 2225 | 2628 |↵
| Regular | 1767 | 1050 | 1344 | 1714 | 2088 | 2417 | 2525 |↵
↵
Overall average difficulty is almost identical.↵
↵
But position-by-position:↵
Educational rounds are consistently easier from A→E, while F problems are actually harder on average.↵
↵
---↵
↵
## 6) Problems whose ratings seem unusual↵
↵
Examples of problems that appear easier/harder than their ratings suggest based on solve counts.↵
↵
### Easier than expected↵
↵
* 1264F — Beautiful Fibonacci Problem↵
(rated 3500, but solved by 1000+ users)↵
↵
### Harder than expected↵
↵
* 2190F — Xor Product↵
* 2066F — Curse↵
* 1967F — Next and Prev↵
* 949F — Astronomy↵
↵
These had surprisingly low solve counts relative to their ratings.↵
↵
---↵
↵
## 7) Contest “symmetry”↵
↵
I also tried measuring how balanced contest difficulty curves are.↵
↵
Average symmetry score:↵
**0.454 / 1**↵
↵
Interpretation:↵
↵
* > 0.7 → balanced progression↵
* < 0.4 → heavily front-loaded↵
↵
Most CF contests lean slightly front-loaded:↵
easy opening problems followed by a sharp wall.↵
↵
---↵
↵
# Running the script↵
↵
Requirements:↵
↵
```bash↵
pip install requests pandas numpy plotly matplotlib tqdm↵
```↵
↵
Run:↵
↵
```bash↵
python deep.py↵
```↵
↵
The script:↵
↵
1. Fetches contests/problems from the CF API↵
2. Performs statistical analysis↵
3. Generates interactive Plotly graphs↵
4. Detects trends/anomalies↵
↵
Fetching everything takes around 15–20 minutes because of API rate limiting.↵
↵
---↵
↵
One thing I still want to analyze is solve timing during contests (for example: when most users solve C/D problems), but that would require a much larger amount of `contest.status` API calls.↵
↵
If anyone has ideas for additional analyses, suggestions are welcome :)↵
↵
please check this result : https://ayushgirigoswami.github.io/codeforces_analysis_report/↵
↵
A few weeks ago I got curious about something most of us probably notice intuitively but rarely measure properly:↵
↵
* Is Codeforces getting harder over time?↵
* Which topics are becoming more common?↵
* Are some problems overrated or underrated?↵
* How different are Educational rounds from regular rounds?↵
↵
So I wrote a Python script that pulls contest/problem data from the CF API, analyzes ratings + tags, and generates interactive visualizations.↵
↵
### Report↵
↵
https://ayushgirigoswami.github.io/codeforces_analysis_report/↵
↵
### Source code↵
↵
https://github.com/Ayushgirigoswami↵
↵
---↵
↵
## Dataset↵
↵
The analysis includes:↵
↵
* 1600 contests↵
* 8354 rated problems↵
* Div.1 / Div.2 / Div.3 / Div.4 / Div.1+2↵
* 2011 → present↵
↵
Average problem rating across the dataset: **1793**↵
↵
---↵
↵
# Some interesting results↵
↵
## 1) Div.1+Div.2 rounds have the widest difficulty spread↵
↵
| Division | Avg Rating | Median | Std Dev |↵
| -------- | ---------- | ------ | ------- |↵
| Div.1 | 2358 | 2400 | 714 |↵
| Div.2 | 1630 | 1600 | 652 |↵
| Div.1+2 | 2096 | 2100 | 927 |↵
| Div.3 | 1429 | 1400 | 513 |↵
| Div.4 | 1213 | 1100 | 412 |↵
↵
Div.1+2 rounds have by far the largest standard deviation.↵
↵
Makes sense in hindsight: these rounds combine easy entry problems with very high-end G/H problems, so the spread becomes huge.↵
↵
Also interesting:↵
even Div.1 A problems average around **1537**, which is already harder than many Div.2 mid-problems.↵
↵
---↵
↵
## 2) Biggest difficulty jumps are usually B→C and C→D↵
↵
Average Div.2 ratings by position:↵
↵
* A ≈ 903↵
* B ≈ 1203↵
* C ≈ 1552↵
* D ≈ 1932↵
* E ≈ 2300↵
* F ≈ 2614↵
↵
The largest jumps are:↵
↵
* B → C : +349↵
* C → D : +380↵
↵
This matches what many contestants experience during contests:↵
B is often straightforward, while C/D is where actual problem solving starts becoming important.↵
↵
For Div.1+2 rounds, the jump near the end becomes even more extreme:↵
↵
* F ≈ 2697↵
* G ≈ 3102↵
* H ≈ 3160↵
↵
---↵
↵
## 3) Topic trends over time↵
↵
### Increasing frequency↵
↵
* greedy↵
* math↵
* constructive algorithms↵
* data structures↵
* binary search↵
* dp↵
* trees↵
* bitmasks↵
* interactive↵
↵
### Decreasing frequency↵
↵
* implementation↵
* geometry↵
↵
The increase in interactive problems during the last few years was especially noticeable.↵
↵
Geometry also appears much less frequently than older rounds.↵
↵
---↵
↵
## 4) Most common tags↵
↵
| Tag | Total |↵
| ----------------------- | ----- |↵
| greedy | 2885 |↵
| math | 2805 |↵
| implementation | 2407 |↵
| dp | 1980 |↵
| constructive algorithms | 1677 |↵
| brute force | 1644 |↵
| data structures | 1620 |↵
| binary search | 1022 |↵
↵
Some observations:↵
↵
* DP is disproportionately common in Div.1.↵
* Implementation dominates Div.2/3 but drops heavily in Div.1.↵
* Graph-related problems appear much more frequently than I expected.↵
↵
---↵
↵
## 5) Educational rounds vs regular rounds↵
↵
This part surprised me.↵
↵
| Type | Overall Avg | A | B | C | D | E | F |↵
| ----------- | ----------- | ---- | ---- | ---- | ---- | ---- | ---- |↵
| Educational | 1769 | 873 | 1118 | 1465 | 1842 | 2225 | 2628 |↵
| Regular | 1767 | 1050 | 1344 | 1714 | 2088 | 2417 | 2525 |↵
↵
Overall average difficulty is almost identical.↵
↵
But position-by-position:↵
Educational rounds are consistently easier from A→E, while F problems are actually harder on average.↵
↵
---↵
↵
## 6) Problems whose ratings seem unusual↵
↵
Examples of problems that appear easier/harder than their ratings suggest based on solve counts.↵
↵
### Easier than expected↵
↵
* 1264F — Beautiful Fibonacci Problem↵
(rated 3500, but solved by 1000+ users)↵
↵
### Harder than expected↵
↵
* 2190F — Xor Product↵
* 2066F — Curse↵
* 1967F — Next and Prev↵
* 949F — Astronomy↵
↵
These had surprisingly low solve counts relative to their ratings.↵
↵
---↵
↵
## 7) Contest “symmetry”↵
↵
I also tried measuring how balanced contest difficulty curves are.↵
↵
Average symmetry score:↵
**0.454 / 1**↵
↵
Interpretation:↵
↵
* > 0.7 → balanced progression↵
* < 0.4 → heavily front-loaded↵
↵
Most CF contests lean slightly front-loaded:↵
easy opening problems followed by a sharp wall.↵
↵
---↵
↵
# Running the script↵
↵
Requirements:↵
↵
```bash↵
pip install requests pandas numpy plotly matplotlib tqdm↵
```↵
↵
Run:↵
↵
```bash↵
python deep.py↵
```↵
↵
The script:↵
↵
1. Fetches contests/problems from the CF API↵
2. Performs statistical analysis↵
3. Generates interactive Plotly graphs↵
4. Detects trends/anomalies↵
↵
Fetching everything takes around 15–20 minutes because of API rate limiting.↵
↵
---↵
↵
One thing I still want to analyze is solve timing during contests (for example: when most users solve C/D problems), but that would require a much larger amount of `contest.status` API calls.↵
↵
If anyone has ideas for additional analyses, suggestions are welcome :)↵
