🧪 Note: This README-style document is designed to help candidates prepare and pass the technical entrance tests of YouCode.

📘 C Programming Exercises - From Beginner to Advanced

This document contains 10 categorized exercises for each major concept in beginner-level C programming, followed by 10 mixed exercises combining all those topics, and 10 advanced exercises for the most challenging problems.

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🔹 1. Variables (10 Exercises)

1. Declare an integer variable and print its value. Input: None Output: The value of a is 10

2. Store your age in a variable and print it. Input: None Output: I am 22 years old.

3. Swap the values of two variables. Input: a = 5, b = 10 Output: a = 10, b = 5

4. Calculate the area of a rectangle using width and height variables. Input: width = 4, height = 6 Output: Area = 24

5. Declare a char variable and print it. Input: letter = 'A' Output: Character is A

6. Create a float variable and assign a decimal value. Input: price = 10.5 Output: Price is 10.50

7. Assign values to three variables and print their sum. Input: a = 2, b = 3, c = 5 Output: Sum = 10

8. Modify a variable using another variable's value. Input: a = 4, b = a * 2 Output: b = 8

9. Declare a constant using #define and print it. Input: #define PI 3.14 Output: PI = 3.14

10. Create variables of all 4 main types and print them. Input: int=1, float=1.5, char='C', double=3.14159 Output: int: 1, float: 1.5, char: C, double: 3.141590

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🔹 2. Data Types (10 Exercises)

1. Print the size of each data type using sizeof(). Output: int: 4 bytes, float: 4 bytes, double: 8 bytes...

2. Declare and assign values to different types. Input: int=5, float=1.1, char='z'... Output: Values printed

3. Convert an int to a float and print. Input: int=5 Output: float=5.000000

4. Use a char variable to store a symbol and print it. Input: char='$' Output: Symbol: $

5. Use a float variable and print it with 2 decimal places. Input: float=3.1459 Output: 3.15

6. Type casting from float to int. Input: float=5.9 Output: int=5

7. Overflow demo with char. Input: char=300 Output: unexpected value (e.g., -56 depending on system)

8. Print ASCII value of a character. Input: char='A' Output: 65

9. Add an int and a float, store in double. Input: int=3, float=2.5 Output: Result=5.5

10. Display limits using limits.h. Output: INT_MAX = 2147483647...

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🔹 3. Conditions (if/else) (10 Exercises)

1. Check if a number is positive or negative. Input: n = -3 Output: Negative

2. Check even or odd. Input: n = 4 Output: Even

3. Compare two numbers. Input: a = 5, b = 2 Output: a is greater

4. Maximum of 3 numbers. Input: 3, 9, 7 Output: Max = 9

5. Vowel or consonant. Input: ch = 'e' Output: Vowel

6. Divisible by 5 and 3. Input: n = 15 Output: Yes

7. Age group. Input: age = 16 Output: Teenager

8. Leap year. Input: 2024 Output: Leap year

9. Score to grade. Input: score = 78 Output: Grade = B

10. Login check. Input: username: admin, password: 1234 Output: Access granted

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🔹 4. Operators (10 Exercises)

1. Add/subtract/multiply/divide two numbers. Input: a=5, b=2 Output: Sum=7, Diff=3, Mul=10, Div=2

2. Modulo operation. Input: 7 % 3 Output: 1

3. Logical AND. Input: n = 7 Output: Yes (between 5 and 10)

4. Logical OR. Input: n = 105 Output: True

5. NOT example. Input: flag = 0 Output: flag is false

6. Increment/decrement. Input: n = 5 Output: ++n = 6, --n = 4

7. Compound assignment. Input: x = 10, x += 5 Output: x = 15

8. Relational operators. Input: a = 3, b = 7 Output: a < b, a != b, etc.

9. Basic calculator. Input: a = 3, b = 2, op = + Output: 5

10. Divisible by both 3 and 7. Input: n = 21 Output: Yes

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🔹 5. Switch (10 Exercises)

1. Weekday name from number. Input: 3 Output: Wednesday

2. Calculator using switch. Input: a=4, b=2, op='*' Output: 8

3. Grade to message. Input: grade = 'A' Output: Excellent

4. Month to season. Input: month = 12 Output: Winter

5. Vowel/consonant with switch. Input: ch='i' Output: Vowel

6. Operation menu. Input: 2 Output: Subtraction selected

7. Weekday/weekend. Input: 7 Output: Weekend

8. Loop + switch menu. Input: menu 1, 2, 3... Output: until user exits

9. Use of default case. Input: invalid = 10 Output: Invalid choice

10. Nested switch. Input: Device: 1, Option: 2 Output: Submenu Option 2

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🔹 6. Loops (10 Exercises)

1. Print 1 to 10. Output: 1 2 3 4 5 6 7 8 9 10

2. Even numbers 1-100. Output: 2 4 6 ... 100

3. Sum first 50 numbers. Output: 1275

4. Factorial. Input: 5 Output: 120

5. Multiplication table. Input: 3 Output: 3 x 1 = 3 ... 3 x 10 = 30

6. Reverse digits. Input: 123 Output: 321

7. Count digits. Input: 4567 Output: 4 digits

8. Fibonacci series. Input: n = 6 Output: 0 1 1 2 3 5

9. do...while password check. Input: wrong, wrong, correct Output: Access granted

10. Prime number check. Input: 7 Output: Prime

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🔁 7. Mixed Practice (10 Exercises)

1. Palindrome number. Input: 121 Output: Palindrome

2. Swap then calculate. Input: a=5, b=3, op='+' Output: a=3, b=5, Sum=8

3. Print vowels in string. Input: "hello" Output: e o

4. Even numbers divisible by 3. Input: range 1–30 Output: 6 12 18 24 30

5. Menu with loop. Input: 1 2 3 0 Output: Add, Subtract, Multiply, Exit

6. Age category. Input: age = 45 Output: Adult

7. Looping calculator. Input: a=2, b=3, op='*', repeat=yes Output: 6

8. Reverse string and check palindrome. Input: "madam" Output: Palindrome

9. Largest digit in number. Input: 5489 Output: 9

10. Login with retry limit. Input: 3 wrong attempts Output: Access denied after 3 tries

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🟢 8. Beginner Challenges (10 Exercises)

1. Simple Number Guessing Game User guesses a number between 1-10. Input: Secret: 7, Guesses: 5, 8, 7 Output: Too low! Too high! Correct in 3 attempts!

2. Temperature Converter Convert between Celsius and Fahrenheit. Input: 25 C to F Output: 25°C = 77°F

3. Simple Interest Calculator Calculate simple interest for given principal, rate, and time. Input: Principal: 1000, Rate: 5%, Time: 2 years Output: Simple Interest = $100

4. Digital Clock Format Convert 24-hour time to 12-hour format. Input: 15:30 Output: 3:30 PM

5. Grade Average Calculator Calculate average of 5 grades and show letter grade. Input: 85, 92, 78, 88, 95 Output: Average: 87.6, Grade: B+

6. Password Strength Checker Check if password meets basic criteria. Input: password123 Output: Weak: Missing uppercase and special character

7. Basic Shape Calculator Calculate area and perimeter of rectangle, circle, triangle. Input: Shape: circle, radius: 5 Output: Area: 78.54, Circumference: 31.42

8. Number to Words (Single Digit) Convert single digit numbers to words. Input: 7 Output: Seven

9. Simple Payroll Calculator Calculate gross pay with overtime. Input: Hours: 45, Rate: $15/hour Output: Regular: $600, Overtime: $112.50, Total: $712.50

10. Basic Unit Converter Convert between common units (meters/feet, kg/pounds). Input: 100 meters to feet Output: 100 meters = 328.08 feet

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🟡 9. Medium Challenges (10 Exercises)

1. Advanced Pattern Generator Generate various number and star patterns. Input: Pattern: pyramid, Height: 5 Output:

       *
      ***
     *****
    *******
   *********
   

2. Roman Numeral Converter Convert numbers to Roman numerals and vice versa. Input: 2024 Output: MMXXIV

3. Quadratic Equation Solver Solve ax² + bx + c = 0 and handle all cases. Input: a=1, b=-5, c=6 Output: x1 = 3, x2 = 2

4. Digital Root Calculator Find digital root by repeatedly summing digits. Input: 9875 Output: 9+8+7+5=29 → 2+9=11 → 1+1=2, Digital Root: 2

5. Binary Calculator Perform arithmetic operations on binary numbers. Input: 1010 + 1100 Output: 10110 (10 + 12 = 22)

6. Anagram Checker Check if two words are anagrams. Input: "listen", "silent" Output: Anagram: Yes

7. Lottery Number Generator Generate unique random lottery numbers. Input: 6 numbers from 1-49 Output: Lucky numbers: 7, 14, 23, 31, 42, 48

8. Grade Book Manager Store and calculate statistics for multiple students. Input: 5 students, 3 subjects each Output: Class average: 78.5, Highest: 95, Lowest: 62

9. Palindrome Sentence Checker Check if sentence is palindrome (ignore spaces/punctuation). Input: "A man, a plan, a canal: Panama" Output: Palindrome: Yes

10. Mortgage Calculator Calculate monthly payment and total interest. Input: Loan: $200,000, Rate: 3.5%, Term: 30 years Output: Monthly: $898.09, Total Interest: $123,312.00

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🔥 10. Advanced Challenges (10 Exercises)

1. Complete Multiplication Table Generator Create a program that generates multiplication tables for any range.

   Input:

   start=3, end=5, max=12
   

   Output:

   Table for 3:
   3 x 1 = 3   3 x 2 = 6   3 x 3 = 9   3 x 4 = 12
   3 x 5 = 15  3 x 6 = 18  3 x 7 = 21  3 x 8 = 24
   3 x 9 = 27  3 x 10 = 30 3 x 11 = 33 3 x 12 = 36
   
   Table for 4:
   4 x 1 = 4   4 x 2 = 8   4 x 3 = 12  4 x 4 = 16
   ...
   

2. Number Pattern Diamond Create a diamond pattern with numbers.

   Input:

   n = 5
   

   Output:

       1
      123
     12345
    1234567
   123456789
    1234567
     12345
      123
       1
   

3. Prime Number Sieve Generate all prime numbers up to N using optimized algorithm.

   Input:

   n = 30
   

   Output:

   2 3 5 7 11 13 17 19 23 29
   

4. Advanced Calculator with Memory Calculator that remembers previous results and supports complex operations.

   Input:

   5 + 3 = 8, MEM, 4 * MEM = 32, CLEAR
   

   Output:

   Result: 32, Memory cleared
   

5. Number Base Converter Convert numbers between different bases (2, 8, 10, 16).

   Input:

   255 from base 10 to base 2
   

   Output:

   11111111
   

6. Perfect Number Generator Find all perfect numbers up to N (number equals sum of its proper divisors).

   Input:

   n = 100
   

   Output:

   6 28
   

7. Matrix Operations Add, subtract, and multiply 2D matrices.

   Input:

   Matrix A: [[1,2],[3,4]]
   Matrix B: [[5,6],[7,8]]
   Operation: multiply
   

   Output:

   [[19,22],[43,50]]
   

8. Text Statistics Analyzer Analyze text for words, characters, vowels, consonants, and frequency.

   Input:

   "Hello World Programming"
   

   Output:

   Characters: 23, Words: 3, Vowels: 6, Consonants: 11
   Most frequent: 'r' (3 times)
   

9. Number Guessing Game with AI Advanced guessing game where computer learns from player patterns.

   Input:

   Secret: 42, Guesses: 50, 25, 37, 44, 42
   

   Output:

   Found in 5 attempts! Pattern detected: binary search
   

10. Financial Calculator Calculate compound interest, loan payments, and investment growth.

    Input:

    Principal: $1000, Rate: 5%, Time: 3 years, Compound: monthly
    

    Output:

    Simple Interest: $150.00
    Compound Interest: $161.47
    Monthly Payment: $30.42
    Total Amount: $1161.47
    

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🏆 Difficulty Progression

• Beginner (Exercises 1-6): Basic syntax, simple logic
• Mixed Practice (Exercise 7): Combining multiple concepts
• Beginner Challenges (Exercise 8): Simple real-world applications
• Medium Challenges (Exercise 9): More complex algorithms and logic
• Advanced Challenges (Exercise 10): Complex algorithms, optimization, advanced applications

📚 Additional Tips

• Practice debugging with different inputs
• Focus on edge cases and error handling
• Optimize your solutions for better performance
• Use proper variable naming and code organization
• Test thoroughly with various input combinations