Saving Christmas
Author: Mihai Nan
📖 Story
This year has been truly special 🎅✨
There have been very, very many good children, more than ever before. So many that Santa Claus realized he wouldn't be able to reach them all by himself to leave them gifts.
After many nights of thinking and consultations with his trusted elves, Santa came up with a magical solution 🪄:
he transformed some of the elves into magical doubles of himself, which help him deliver gifts faster throughout the world.
Unfortunately, the magic also created confusion...
In the images captured during Christmas night, it's no longer clear how many Santa Clauses actually appear.
For the magic to work and Christmas to be saved, the elves need your help!

🎯 Objective
For each image received, you must determine how many Santa Clauses appear in the image.
For this, you need to implement an artificial intelligence-based solution that receives an image as input and predicts a natural number representing the number of Santa Clauses.
📥 Input Data
- A set of images that can contain between 0 and multiple Santa Clauses (you can apply exploratory data analysis on the training set to determine the maximum number of Santa Clauses in an image)
- The
train.csvfile which contains data that can be used for model training and has the following format:
image_path,number
images/image_0214.png,0
images/image_0187.png,4
images/image_0000.png,0
- The
test.csvfile which contains paths to images that need to be analyzed independently to predict the number of Santa Clauses that appear. This file has the following format:
image_path
images/image_0119.png
images/image_0227.png
images/image_0160.png
📤 Output Data
You will need to generate a submission.csv file that will have the following format:
image_path,number
images/image_0119.png,1
images/image_0227.png,2
images/image_0160.png,3
where for each image in the test set we have specified the path and the predicted number.
🧮 Evaluation System
For each image, the score is calculated based on the absolute difference
between the predicted number and the real number of Santa Clauses:
| Absolute Difference | Points Awarded |
|---|---|
| 0 | 1 point |
| 1 | 1 point |
| 2 | 0.5 points |
| 3 | 0.25 points |
| ≥ 4 | 0 points |
Absolute difference =
|predicted_number - real_number|
✅ Example
- Real number of Santa Clauses: 4
- Predicted number: 6
The difference is |6 - 4| = 2 → 0.5 points
🎁 Final Score
The final score is calculated starting from the sum of points obtained for all images in the test set. Based on this value, the final score is calculated according to the rules:
- If the total sum is below 50, the final score will be 0 points.
- If the total sum is above 95, the final score will be 100 points.
- If the total sum is between 50 and 95, the final score will be calculated proportionally between 0 and 100 points, using linear interpolation.
Help Save Christmas through the most accurate counting possible 🎄✨
Every Santa counts!
🎅 Good luck!