Challenges

A collection of challenges I made for C++.
Status:

Programs

• Challenge 1

  • Write a program that outputs the largest possible signed/unsigned int number (char, short, int, long, long long)
  • Without knowing the number of bits used internally in the system for each data type.
  • Hints:
    • Study the possible operators for whole numbers.
    • The ~-Operator inverts all bits, making the maximum largest unsigned number of 0.
    • For signed numbers one bit is used for the sign (two's complement representation).
  • Solution

• Challenge 2

  • Write a program that requires three integers as input
  • The first is meant as the beginning of a range of numbers
  • The second as the end of the range
  • The program should check if the third number is within the range including the limits
  • Output a corresponding message
  • Output an error message if the number for the beginning > the number for the end
  • Solution

• Challenge 3

  • Write a program that requires three integers as input
  • Output the biggest number of the three integers
  • Solution

• Challenge 4

  • Write a program that requires an integer as input
  • Create a loop that outputs a given number in binary
  • Use bit operations to check which bits of the number are set
  • Hints:
    • Use the number 1, shifted by 0 to e.g. 31 bit positions, as a mask
  • Possible results:
    • 5 -> 00000000000000000000000000000101
    • -5 -> 11111111111111111111111111111011
  • Solution

• Challenge 5

  • Write a program that calculates the sum of all natural number from n1 to n2
  • a) With a for loop
  • b) With a while loop
  • c) With a do while loop
  • d) Without a loop
  • Assume n2 >= n1
  • Solution

• Challenge 6

  • Write a struct called Person:
    • String Firstname
    • String Lastname
    • Int Age
  • Use cin(input via keyboard) to assign values to the struct
  • Output entered values via struct
  • Solution

• Challenge 7

  • Write a program that requires a string that represents a natural number and only consists of digits as input
  • Example:
    • "17462309"
  • a) Convert the string to a number x of type long
  • b) Calculate the checksum of z
  • Output the converted number and the checksum
  • Solution

• Challenge 8

  • Write a program that requires a natural number as input
  • Convert the input to a Roman number
    • const string CHARACTERS = "IVXLCDM"
  • Syntax rules
    • No digit except 'M' is allowed more than three times in a row
  • Example
    • Input: "4" = "IIII" is wrong
    • Input: "4" = "IV" is right
  • Output the converted number
  • Solution

• Challenge 9

  • Write a program that can read any number in the range of -99 to +100(inclusive)
  • The number range is divided into 10 equal large intervals
  • Once a number outside the range is entered, end the input
  • Output for each interval how many numbers have been entered
  • Hints:
    • Use const for -99, +100 and so on
    • Use a vector to save the intervals
  • Solution

• Challenge 10

  • Write a program that requires a natural number > 0
  • • If the number is even, divide by 2
    • If not, multiply it by 3 and add 1
  • • If the resulting number is greater than 1, apply step a again
    • If not, the process is finished
  • Output every result from the algorithm
  • Output every new biggest number and add a pause
  • Output how many iterations were needed
  • Solution

• Challenge 11

  • Write a program that prints the contents of a file in hexadecimal form
  • First output 16 letters then the 16 associated hex codes per line
  • Solution

• Challenge 12

  • Write a program that outputs statistics for a text file
  • Example:
    • Number of characters = 16437
    • Number of words = 2526
    • Number of lines = 220
  • A word is defined as an uninterrupted sequence of character
  • Umlauts do not count as characters because they are not part of ASCII
  • The number of characters should not contain the end-of-line identifier
  • Solution

• Challenge 13

  • • Write a program that can read any number of entries from a file like below
    • Example.txt

     Bob Ross
     123456
     Kappa Pride
     746453
     Kappa Claus
     6329430
     #
    

    • Use a struct named Student.
    • It should contain the name and the associated student number as a string
    • The data should be saved in a vector
    • Output the contents of the vector
  • • Ask for a student number
    • Output name(or "not found")
    • Do step 2 again until the user enters 'x' or 'X'
  • Solution

• Challenge 14

  • Write a program that requires 3 integers
  • Ask for hours, minutes and seconds
  • Create a function called ConvertToSeconds(int hours, int minutes, int seconds)
  • Convert the user input to seconds
  • Output total seconds
  • Solution

• Challenge 15

  • Write a program that requires 1 double and 1 int
  • Ask for a double number and int exponent
  • Create a function called power(x, y)
  • Calculate the power with the function
  • Output the result
  • Solution

• Challenge 16

  • Write a program that requires a string
  • Create a function called reverseString(String)
    • Reverse the order of the characters in the string
  • Output result
  • Solution

• Challenge 17

  • Write a program that requires a string
  • Create a function called isAlphanumerical(String)
    • Return true if string only contains letters and digits
    • Else return false
  • Output result
  • Solution

• Challenge 18

  • Write a template function getType(T)
  • Use template specialisation to return the type of the parameter T as string
  • Solution

• Challenge 19

  • Create a class called Person
    • Attribute: Name, Age, Sex
    • Methods: getName(), getAge(), getSex(), setName(), setAge(), setSex()
  • Create enum class Sex
    • Male, Female
  • Create instance of Person with name = Kappa Pride, age = 1337, sex = male
  • Output name and age of person
  • Output name and sex of person
  • Add 1 year to current age
  • Output name and new age of person
  • Change lastname to Claus
  • Output new name
  • Solution

• Challenge 20

  • Create a class called IntAmount
    • void add(int)
    • void remove(int)
    • bool isMember(int)
    • std::size_t size()
    • void display()
    • void clear()
    • int getMax()
    • int getMin()
    • To save values add vector
  • Example usage:

   IntAmount amount;
  
   amount.add(2);
   amount.add(-9);
   amount.add(2);
   amount.remove(99);
   amount.remove(-9);
   amount.display();
   amount.clear();
  
   for(int i = 17; i < 33; ++i)
   	amount.add(i * i);
  
   std::cout << "Amount: " << amount.size() << " Minimum: " << amount.getMin() << '\n';
   std::cout << "amount.isMember(1337) " << amount.isMember(1337) << '\n';
  

  • Solution

• Challenge 21

  • Write a function void strcopy(char* target, const char* source)
  • Copy the content of the string source into the string target
  • Overwrite the previous content of target
  • It is required that target is big enough to copy source into target
  • Solution

• Challenge 22

  • Write a function char* strDuplicate(const char* s)
  • Create a duplicate of s with new
  • Return a pointer to the beginning of the duplicate
  • Solution

• Challenge 23

  • Write a program that sorts the array below in Alphabetical order
  • Given is: const char *sField[]={"one","two","three","four","five","six","seven","eight",nine","ten"};
  • Solution

• Challenge 24

  • Write a function void removeSpaces(char* s)
    • Remove all spaces from s
  • Example: "a bb ccc" = "abbccc"
  • Use pointers
  • Solution

• Challenge 25

  • Write a program that outputs file names defined from command line
  • Example: Challenge25 file1.cpp XXX file2.cpp
    • Output file1.cpp and file2.cpp in console
    • If file XXX is not found output error message: "File XXX not found!"
  • Solution

• Challenge 26

  • Write a program tat prints all names from a file
    • It starts with a letter, then follow any number of letters and numbers
    • Underscore also counts as a letter
  • Solution

• Challenge 27

  • Write a class Format
    • Formatting numbers
    • Automatically extend width to avoid information loss
  • Example usage:

   Format f(12, 3); //Output 12 characters wide, 3 decimal places
   std::cout << f.toString(789,906625) << '\n'; //= SSSSS789,907 | S = empty space
   std::cout << f.toString(-123456789.906625) << '\n'; //= -123456789,907
  

  • Solution

• Challenge 28

  • Simulate a party
    • Example

     int main()
     {
         Member otto("Otto");
       	Member andrea("Andrea");
       	Member jens("Jens");
       	Member silvana("Silvana");
       	Member miriam("Miriam");
       	Member paul("Paul");
       	//Vector with memory addresses
       	std::vector<Member*> all {&otoo, &andrea, &jens, &silvana, &miriam, &paul};
       	andrea.getsToKnow(jens);
       	silvana.getsToKnow(otto);
       	paul.getsToKnow(otto);
       	paul.getsToKnow(silvana);
       	miriam.getsToKnow(andrea);
       	jens.getsToKnow(miriam);
       	jens.getsToKnow(silvana);
       	if(jens.knows(andrea))
       	    std::cout << "Jens knows Andrea" << '\n';
       	//Output of all members indicating who knows whom:
       	for(auto memberPtr : all)
       	{
       	    std::cout << memberPtr->giveName() << " knows: ";
       	    memberPtr->printKnown();
         }
     }
    

  • Create class Member
    • getsToKnow(Member&) //To get to know each other
    • knows(Member&)
    • giveName()
    • void printKnown()
    • std::vectorstd::string known
    • "alex.getsToKnow(alex);" should be ignored
  • Vector<Member*>
    • Use it to output names and known
    • Point to the original object with pointers
  • Hint:
    • Comparison of the addresses of two objects shows whether they are identical
    • Copies can be the same, but they are different objects
  • Solution

• Challenge 29

  • Write a stack template called MyStack
    • Use a std::vector object as container for data
  • Solution

• Challenge 30

  • Write a class called Person
    • Abstract
    • std::string Firstname
    • std::string Lastname
    • getLastname()
    • getFirstname()
    • toString() //Return Firstname + Lastname
  • class Student
    • Inherit Person
    • std::string StudentNumber
    • toString() //Return Firstname + Lastname + StudentNumber
    • getStudentNumber()
    • setStudentNumber()
  • class Professor
    • Inherit Person
    • std::string SubjectArea
    • toString() //Return Firstname + Lastname + SubjectArea
    • getSubjectArea()
    • setSubjectArea()
  • Example usage:

   std::vector<Person*> people;
   people.push_back(new Student("Pride", "Kappa", "635374"));
   people.push_back(new Professor("Respect", "Dr. Dis", "Killing"));
   people.push_back(new Student("Ross", "Bob", "123429"));
  
   for(auto personPtr : people)
   	std::cout << personPtr->getFirstname() << '\n';
  
   for(auto personPtr : peolple)
   	std::cout << perosnPtr->toString() << '\n';
  

  • Example output:

   Kappa Pride
   Dr. Dis
   Bob
   Student Kappa Pride, Stud.No.: 635374
   Prof. Dr. Dis Respect, Subject area: Killing
   Student Bob Ross, Stud.No.: 123429
  

  • Solution

• Challenge 31

  • Create a program that asks for the users name, age and nickname
  • Output the information back in format: Your name is ..., you are ... years old and your username is ...
  • Extra challenge: Save the information in a file for later access.
  • Solution

• Challenge 32

  • Create a program that will guess numbers between 1-100 and respond appropriately based on whether the user says that the number is too high or too low.
  • Example output: Is your number ...? (Y)es, it's (h)igher, it's (l)ower
  • Extra challenge: Make the starting value random.
  • Solution

• Challenge 33

  • Create a programm that calculates F = M * A
  • Example output:

   What is the acceleration? ...
   What is the mass? ...
  
   The Force is ...
  

  • Example output(Extra Challenge):

   What would you like to calculate?
   Type F for force, M for mass, or A for acceleration:
   ...
   The force/mass/acceleration is ...
  

  • Extra challenge: Also add functionality to calculate mass or acceleration
  • Solution