Building a Leaderboard for a Number Guessing Game using Selection Sort

Introduction

What is a Number Guessing Game?

A number guessing game is a simple game where:

The system generates a random number
The player tries to guess that number
The system gives hints like:
"Too high"
"Too low"
The game continues until the correct number is guessed

How Performance is Measured

The number of attempts taken by a player is recorded
The difficulty level (Easy, Medium, Hard) may also be chosen

In a number guessing game, just finding the correct number is not enough.
We also need to compare players and rank them based on their performance.

This can be done using a leaderboard system, where players are sorted based on:

• Difficulty level
• Number of attempts

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Problem Statement

The task is to:

1. Show the leaderboard details
2. Sort the leaderboard based on:

• Difficulty (Easy → Medium → Hard)
• Attempts (less attempts = better rank)

Example Input

Alice   Hard    7
Bob     Easy    3
Charlie Medium  5
David   Easy    2

Expected Output

David   Easy    2
Bob     Easy    3
Charlie Medium  5
Alice   Hard    7

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Concept Used: Selection Sort

Selection Sort works in a simple way:

1. Find the smallest element
2. Place it in the correct position
3. Repeat for the remaining elements

In this problem:

• “Smallest” means:

  • Easier difficulty first
  • If same difficulty → fewer attempts

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Step 1: Store Leaderboard Data

leaderboard = [
    {"name": "Alice", "difficulty": "Hard", "attempts": 7},
    {"name": "Bob", "difficulty": "Easy", "attempts": 3},
    {"name": "Charlie", "difficulty": "Medium", "attempts": 5},
    {"name": "David", "difficulty": "Easy", "attempts": 2}
]

Explanation

• leaderboard is a list
• Each player is stored as a dictionary

• Keys:

  • name → player name
  • difficulty → level
  • attempts → number of tries

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Step 2: Define Difficulty Order

order = {"Easy": 1, "Medium": 2, "Hard": 3}

Explanation

• Difficulty is text, so we convert it into numbers
• Easy = 1, Medium = 2, Hard = 3
• This helps in comparison during sorting

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Step 3: Selection Sort Code

n = len(leaderboard)

for i in range(n):
    min_index = i

    for j in range(i + 1, n):
        if (order[leaderboard[j]["difficulty"]], leaderboard[j]["attempts"]) < \
           (order[leaderboard[min_index]["difficulty"]], leaderboard[min_index]["attempts"]):
            min_index = j

    leaderboard[i], leaderboard[min_index] = leaderboard[min_index], leaderboard[i]

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Line-by-Line Explanation

Line 1

n = len(leaderboard)

• Finds the total number of players

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Line 2

for i in range(n):

• Outer loop
• Moves from first position to last

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Line 3

min_index = i

• Assumes current position has the smallest element

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Line 4

for j in range(i + 1, n):

• Inner loop
• Checks remaining elements

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Line 5 (Important)

if (order[leaderboard[j]["difficulty"]], leaderboard[j]["attempts"]) < (order[leaderboard[min_index]["difficulty"]], leaderboard[min_index]["attempts"]):

Explanation:

• Compares two players
• First compares difficulty
• Then compares attempts

So:

• Easy comes before Medium
• If same → fewer attempts wins

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Line 6

min_index = j

• Updates the index of the smallest player

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Line 7

leaderboard[i], leaderboard[min_index] = leaderboard[min_index], leaderboard[i]

• Swaps the players
• Places the smallest element in correct position

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Step 4: Display Sorted Leaderboard

for player in leaderboard:
    print(player)

Explanation

• Loops through sorted list
• Prints each player

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Output

{'name': 'David', 'difficulty': 'Easy', 'attempts': 2}
{'name': 'Bob', 'difficulty': 'Easy', 'attempts': 3}
{'name': 'Charlie', 'difficulty': 'Medium', 'attempts': 5}
{'name': 'Alice', 'difficulty': 'Hard', 'attempts': 7}

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Conclusion

This project uses:

• Basic data structures (list and dictionary)
• Selection Sort for ordering

Selection Sort is simple to understand and works well for small datasets like this leaderboard.

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