Stackup | Challenges

delegates.md

1. To‑Do Manager — Predicate bilan filtrlash

Konsol ilovasi yozing:

1. Task nomli record yarating (Id, Title, IsDone).
2. List<Task> saqlang.
3. Foydalanuvchiga quyidagi menyu ko‘rsating: add / list / list-done / toggle / exit.
4. add — sarlavha so‘rang, yangi Task qo‘shing.
5. list — hamma vazifalarni ko‘rsating.
6. list-done — Predicate<Task> orqali faqat IsDone == true bo‘lganlarini filtr qiling.
7. toggle — Id bo‘yicha IsDone qiymatini o‘zgartiring.

Talablar
• Filtrlash logikasini alohida static metodda Predicate<Task> parametr bilan yozing.
• Id autoincrement bo‘lsin.
• Har bir buyruqdan so‘ng foydalanuvchi menyuga qaytadi.

Misol

cmd> add
Title: Buy milk
Task added (Id: 1)
cmd> add
Title: Write lab report
Task added (Id: 2)
cmd> list
1. Buy milk [ ]
2. Write lab report [ ]
cmd> toggle
Enter Id: 1
Task 1 marked done.
cmd> list-done
1. Buy milk [X]
cmd> exit

---

2. Temperatur kuzatuvchi — event + Action<double>

Sensordan kelayotgan har bir temperatura qiymatini konsolga chiqaradigan, lekin 40 °C dan oshsa ogohlantirish beradigan dastur yozing.

1. TemperatureSensor klassi
   • event Action<double> TemperatureMeasured;
   • void Measure(double value) metodi eventni chaqirsin.

2. TemperatureMonitor klassi
   • Konstruktorida sensorga subscribe qiladi.
   • Delegat: har qiymatni chiqaradi; agar value > 40, High temperature! deb yozadi.

3. Program
   • Sensor yaratadi, monitor ulaydi.
   • while ichida foydalanuvchidan qiymat olib, sensor.Measure() chaqiradi.

Qoida: Eventni ?.Invoke bilan chaqiring; subscription / unsubscription ni to‘g‘ri bajaring.

Misol

Input temp (or x): 36.5
Temp: 36.5°C
Input temp (or x): 42
Temp: 42°C  --> High temperature!
Input temp (or x): x
Exiting...

---

3. Matnni ketma‑ket o‘zgartirish — Func<string,string> pipeline

1. List<Func<string,string>> konveyer yarating.

2. Menyu buyruqlari:

   • upper – matnni katta harflarga o‘tkazish funksiyasini qo‘shish
   • trim – bo‘sh joylarni olib tashlaydigan funksiyani qo‘shish
   • reverse– matnni teskari qiluvchi funksiyani qo‘shish
   • run – foydalanuvchidan satr olib, pipeline bo‘yicha ishlatish
   • exit

3. Agar pipeline bo‘sh bo‘lsa, run satrni o‘zgartirmaydi.

Misol

cmd> upper
Added UPPER.
cmd> reverse
Added REVERSE.
cmd> run
Enter text: hello
Result: OLLEH
cmd> exit

---

4. Chegirma strategiyasi — Func<decimal,decimal>

Internet‑do‘kon uchun narx hisoblash dasturi yozing.

• Dictionary<string, Func<decimal, decimal>> strategies yarating:
  • none → narxni o‘zgartirmaydi
  • vip → 20 % chegirma
  • blackfriday → 50 % chegirma
• Foydalanuvchidan narx va strategiya nomi so‘raladi.
• Belgilanmagan nom uchun none ishlatiladi.
• Yakuniy narxni 2 kasr belgisi bilan formatlab chiqaring.

Misollar

Price: 200
Discount type (none/vip/blackfriday): vip
Final: 160.00

Price: 100
Discount type (none/vip/blackfriday): student
Final: 100.00

---

5. Bank hisob raqami — event EventHandler<decimal>

Bank hisobida balans o‘zgarishini kuzatib boruvchi dastur yozing.

1. BankAccount klassi

   • public event EventHandler<decimal>? BalanceChanged;
   • Deposit(decimal amount) va Withdraw(decimal amount) balansni o‘zgartiradi; har ikkisi eventni chaqiradi.
   • Withdraw balans yetarli bo‘lmasa xabar chiqarib, event chaqirmasin.

2. Program

   • Hisob yaratadi.
   • Eventga obuna bo‘lib, Balance: XX.XX formatida balansni chiqaradi.
   • Foydalanuvchidan d (deposit), w (withdraw) yoki x (exit) va summani oladi.

Eʼtibor: Eventni trigger qilayotganda ?.Invoke(this, balance) dan foydalaning.

Misol

Command (d/w/x): d
Amount: 150
Balance: 150
Command (d/w/x): w
Amount: 70
Balance: 80
Command (d/w/x): w
Amount: 100
Insufficient funds.
Command (d/w/x): x
Goodbye!

General.md

1. Convert Age

Write a C# function that converts given age in years into days.

• consider a year has 365 days
• ignore leap years

Example

Input	Output
65	23725
0	0
20	7300

public int AgeInDays(int ageInYears)
{
    // your code here
}

---

2. Basketball Score

You are counting total score for a basketball game. In basketball, players can score 2 pointer shots and 3 pointer shots. Given the number of 2 pointers and 3 pointers, you need to calculate the total score.

Example

Input	Output
1 1	5
7 5	29
38 8	100

public int CalculateTotalScore(int twoPointers, int threePointers)
{
    // your code here
}

---

3. Formal Name

Given the first name, last name and a boolean representing if a person is a male, write a C# function which returns the formal name in {Mr.|Mrs.} {First name} {Last name} format.

• First name and last name should always be Title Case

Example

Input	Output
"john" "DOE" true	Mr. John Doe
"wahid" "AbDuHaKimOv" true	Mr. Wahid Abduhakimov
hermione Granger false	Mrs. Hermoine Granger

public string FormalName(string firstName, string lastName, bool isMale)
{
    // your code here
}

---

Instructions.md

📘 Problem Submission Instructions

Follow the steps below to submit your solutions correctly. This will help ensure your work is reviewed and organized properly. ✅

---

🛠️ How to Submit Your Solutions

Please submit your answers as comments on this Gist by following these instructions:

1️⃣ Solve the Problem Locally

• Open the problems in your Visual Studio Code (or your preferred C# editor).
• Solve the problem(s) in a .cs file.
• Save your solution when you’re done.

---

2️⃣ Take a Snapshot 📸

• In VS Code, take a screenshot (snapshot) of your solution code window showing:
  • The solution code
  • Problem number and name as a comment (optional but helpful)
• Make sure the code is readable in the snapshot.

---

3️⃣ Post a Comment 💬

For each solution, do the following:

• Add a new comment to this Gist.
• In the comment, include:
  • ✏️ Problem Number (e.g., Problem 3)
  • 🖼️ Your screenshot of the solution as an attachment
  • 💡 Optionally, include any notes or explanation

Example Comment:

Numbers.md

1. Checked addition

Write a C# function to add two integers and return the result. Return -1 if the addition overflows.

Example

Input	Output
1 2	3
2147483647 2147483647	-1

public int CheckedAdd(int a, int b)
{
    // your code here
}

---

2. Clean number

Write a C# function which accepts a string with numbers, spaces and special characters in it. Clean out the all non-numeric characters and parse the string into single BigInteger type.

If the string doesnt contain numeric characters, then return a BigInteger with value 0.

Example

Input	Output
1 2	12
21##47 48asdf3647	2147483647
asdf<>?<	0

public BigInteger CleanNumber(string str)
{
    // your code here
}

---

3. Add Transactions

You are building a financial transaction tracking system for a large corporation. Due to the scale of operations, transactions involve extremely large amounts of money represented as strings. Implement a function AddTransaction that takes two transaction amounts represented as strings and returns their sum.

Example

Input	Output
"" ""	0
"1231231231231231233123123123123123123123" "1231231231231231233123123123123123123123"	2462462462462462466246246246246246246246

public BigInteger AddTransactions(string amount1, string amount2)
{
    // your code here
}

---

4. Predict Population

In a demographic study, you're analyzing population growth over several decades. Implement a function PredictPopulation that takes the initial population size and growth rate and predicts the population after a certain number of years.

Example

Input	Output
500000 3 10	48828125000000000000
1000 1 20	1000

public BigInteger PredictPopulation(BigInteger initialPopulation, int growthRate, int years) 
{
    // Your code here
}

---

5. Currency Conversion

You are building a currency conversion tool that needs to accurately convert an amount from one currency to another. Implement a function ConvertCurrency that takes a decimal amount in one currency and a float exchange rate, and returns the equivalent amount in the target currency.

Example

Input	Output
1000 12663.90	12663900

public decimal ConvertCurrency(decimal amount, float rate) 
{
    // Your code here
}

---

String Operations.md

1. Reverse String

Write a C# function to reverse a given string without using any built-in string reversal functions.

Example

Input	Output
hello	olleh
world	dlrow

public string Reverse(string str)
{
    // your code here
}

---

2. Is it anagram?

Implement a function to check if two strings are anagrams of each other.

Example

Input	Output
silent listen	true
hello world	false

public bool AreAnagrams(string str1, string str2)
{
    // your code here
}

---

3. Longest Palindrome

Write a program to find the longest palindrome substring within a given string.

Example

Input	Output
forgeeksskeegfor	geeksskeeg
abracadabra	aca
aba	aba

public string LongestPalindromeWithin(string str)
{
    // your code here
}

---

4. Remove Duplicates

Implement a function to remove duplicate characters from a string without using any additional data structures.

Example

Input	Output
hello	helo
world	world
abracadabra	cd

public string RemoveDuplicates(string str)
{
    // your code here
}

---

5. Valid Palindrome

Create a method to check if a given string is a valid palindrome, considering only alphanumeric characters and ignoring cases.

Example

Input	Output
race car	true
race a car	false
A man, a plan, a canal: Panama	true

public bool IsValidPalindrome(string str)
{
    // your code here
}

---

6. First non-repeated character

Write a program to find the first non-repeated character in a given string.

Example

Input	Output
hello	h
abracadabra	c

public char FirstNonRepeatedCharacter(string str)
{
    // your code here
}

---

7.

Implement a function to perform string compression, where consecutive characters are replaced with the count of the character followed by the character itself.

Example

Input	Output
aabcccccaaa	a2b1c5a3
aabbcc	a2b2c2

public string Compress(string str)
{
    // your code here
}

---

3.2

3.3

3.4

3.5

3.6

3.7