Introduction to Practice Problems in C#

Introduction to Practice Problems

Welcome to the practical segment of our C# programming journey! Today, we'll apply the knowledge from past lessons to solve two practice problems using advanced C# data structures: queues, deques, and sorted dictionaries with custom class keys.

First Practice Problem: Implementing Queues with Deques

Analyzing the First Problem Solution

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using System;
using System.Collections.Generic;

class Queue
{
    private LinkedList<string> buffer;

    public Queue()
    {
        // Initializing an empty queue
        buffer = new LinkedList<string>();
    }

    // Adding (enqueueing) an item to the queue
    public void Enqueue(string val)
    {
        buffer.AddLast(val);
    }

    // Removing (dequeuing) an item from the queue
    public string Dequeue()
    {
        if (IsEmpty())
        {
            throw new InvalidOperationException("Queue is empty");
        }
        string value = buffer.First.Value;
        buffer.RemoveFirst();
        return value;
    }

    // Checking if the queue is empty
    public bool IsEmpty()
    {
        return buffer.Count == 0;
    }

    // Checking the size (number of items) in the queue
    public int Size()
    {
        return buffer.Count;
    }

    public static void Main(string[] args)
    {
        Queue restaurantQueue = new Queue();

        restaurantQueue.Enqueue("Order 1");
        restaurantQueue.Enqueue("Order 2");

        Console.WriteLine("Dequeued: " + restaurantQueue.Dequeue());
        Console.WriteLine("Dequeued: " + restaurantQueue.Dequeue());
    }
}

using System;
using System.Collections.Generic;

class Player : IComparable<Player>
{
    public string Name { get; }
    public int Score { get; }

    public Player(string name, int score)
    {
        Name = name;
        Score = score;
    }

    public int CompareTo(Player other)
    {
        int scoreComparison = Score.CompareTo(other.Score);
        if (scoreComparison == 0)
        {
            return Name.CompareTo(other.Name);
        }
        return scoreComparison;
    }

    public override bool Equals(object obj)
    {
        if (this == obj) return true;
        if (obj == null || GetType() != obj.GetType()) return false;
        Player player = (Player)obj;
        return Score == player.Score && Name == player.Name;
    }

    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 23 + Name.GetHashCode();
            hash = hash * 23 + Score.GetHashCode();
            return hash;
        }
    }

    public override string ToString()
    {
        return $"({Name}, {Score})";
    }

    public static void Main(string[] args)
    {
        SortedDictionary<Player, int> scores = new SortedDictionary<Player, int>();

        Player player1 = new Player("John", 900);
        Player player2 = new Player("Doe", 1000);

        // Adding players to the SortedDictionary
        scores[player1] = player1.Score;
        scores[player2] = player2.Score;

        // Print SortedDictionary
        foreach (var entry in scores)
        {
            Console.WriteLine(entry.Key); // e.g., (John, 900)
        }
    }
}

using System;
using System.Collections.Generic;

class Player : IComparable<Player>
{
    public string Name { get; }
    public int Score { get; }

    public Player(string name, int score)
    {
        Name = name;
        Score = score;
    }

    public int CompareTo(Player other)
    {
        int scoreComparison = Score.CompareTo(other.Score);
        if (scoreComparison == 0)
        {
            return Name.CompareTo(other.Name);
        }
        return scoreComparison;
    }

    public override bool Equals(object obj)
    {
        if (this == obj) return true;
        if (obj == null || GetType() != obj.GetType()) return false;
        Player player = (Player)obj;
        return Score == player.Score && Name == player.Name;
    }

    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 23 + Name.GetHashCode();
            hash = hash * 23 + Score.GetHashCode();
            return hash;
        }
    }

    public override string ToString()
    {
        return $"({Name}, {Score})";
    }

    public static void Main(string[] args)
    {
        SortedDictionary<Player, int> scores = new SortedDictionary<Player, int>();

        Player player1 = new Player("John", 900);
        Player player2 = new Player("Doe", 1000);

        // Adding players to the SortedDictionary
        scores[player1] = player1.Score;
        scores[player2] = player2.Score;

        // Print SortedDictionary
        foreach (var entry in scores)
        {
            Console.WriteLine(entry.Key); // e.g., (John, 900)
        }
    }
}

using System;
using System.Collections.Generic;

class Player : IComparable<Player>
{
    public string Name { get; }
    public int Score { get; }

    public Player(string name, int score)
    {
        Name = name;
        Score = score;
    }

    public int CompareTo(Player other)
    {
        int scoreComparison = Score.CompareTo(other.Score);
        if (scoreComparison == 0)
        {
            return Name.CompareTo(other.Name);
        }
        return scoreComparison;
    }

    public override bool Equals(object obj)
    {
        if (this == obj) return true;
        if (obj == null || GetType() != obj.GetType()) return false;
        Player player = (Player)obj;
        return Score == player.Score && Name == player.Name;
    }

    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 23 + Name.GetHashCode();
            hash = hash * 23 + Score.GetHashCode();
            return hash;
        }
    }

    public override string ToString()
    {
        return $"({Name}, {Score})";
    }

    public static void Main(string[] args)
    {
        SortedDictionary<Player, int> scores = new SortedDictionary<Player, int>();

        Player player1 = new Player("John", 900);
        Player player2 = new Player("Doe", 1000);

        // Adding players to the SortedDictionary
        scores[player1] = player1.Score;
        scores[player2] = player2.Score;

        // Print SortedDictionary
        foreach (var entry in scores)
        {
            Console.WriteLine(entry.Key); // e.g., (John, 900)
        }
    }
}

Introduction to Practice Problems

First Practice Problem: Implementing Queues with Deques

Analyzing the First Problem Solution

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Second Practice Problem: Using Sorted Dictionaries with Custom Class as a Key

Analyzing the Second Problem Solution

Lesson Summary