/* This code is solution for challenge: ________________________________________________________________________ Mersenne Prime. A Mersenne prime is a prime number that is one less than a power of two. It is a prime number of the form 2^n-1 for some integer n. For example: Input: 3 Output: true (3 is a prime number and 3=2^2-1) Input: 31 Output: true (31 is a prime number and 31=2^5-1) Input: 17 Output: false (17 is a prime number but it is not of the form 2^n-1) Write a program to check if the user input is a Mersenne prime or not. Bonus: Print all the Mersenne primes in a given range. ______________________________________________________________ EXAMPLE #1: For input: r [ENTER] 1 [ENTER] 50 [SUBMIT] You will get on the screen: You choose range-search mode. Entered first number in the range: 1. Entered last number in the range: 50. all Mersenne primes in the given range [1, 50]: [ 1 3 7 31 ]. That's all for now, run again. ______________________________________________________________ EXAMPLE #2: For input: S [ENTER] 524287 [SUBMIT] You will get on the screen: You choose single number search mode. You entered for research number: 524287 You enter a Mersenne prime number. Come again, good bye! */ #include #include #include #include // template function for simple message output template void pOL(messageType message){ std::cout << message; } /* Base class "storage" has private: messages for display, and private container for answer from user; public containers, methods and destructor: destructor simply send "come again" message, boolean "approved" for validating input from user, methods for send messages input validity or result, boolean "mode" for initilizing mode of program - number research or range research, also created a virtual empty methods for overloading it in the derrived class and using that overloaded methods by the base class pointer to derrived class. */ class storage{ // There is no need to share this containers and methods with derrived // class and main program private: // messages represent as strings, they kept private because doesn't uses // in other parts of programm std::string modeSingle = "You choosed single number for research."; std::string modeRange = "You choosed range of numbers for research."; std::string incorrect = "This input is incorrect.\n"; std::string comeAgain = "\nThat's all for now, run again.\n"; // char container for answer letter from user kept stored privetly char answer; // Main program need this containers and methods public: // true - for number, false - for range bool mode = true; // approved = true - correct input, false - incorrect input bool approved = true; // Method that show to user options of the program void openDialog(){ // read mode from user std::cin >> answer; } // Method print corresponding message about "correct" or "incorrect" input void validateDialog(){ // Setting range-search mode if ( (answer == 's') || (answer == 'S') ){ pOL(modeSingle); mode = true; } // Setting range-search mode else if ( (answer == 'r') || (answer == 'R') ){ pOL(modeRange); mode = false; } // Not allow to program work when input invalid else approved = false; // Immidiately send error message in case wrong input if (!approved) pOL(incorrect); } // Prepared virtual empty method for collecting number for research virtual void getNumber(){} // Prepared virtual empty method for collecting range for research virtual void getRange(){} // Virtual empty method for sening result message if base class pointer // will initilize it - because of keyword "virtual" derrived class overload // method closeDialog() will be used virtual void closeDialog(){} // Destructor simply send message to user asking run program again ~storage(){ pOL(comeAgain); } }; /* Derrived class numberResearcher contain: private messages for user, container for collecting number, clock_t variables for counting time; protected containers - vector for prime numbers, boolean for primes and time exeception error, method checkMNumber() return status of number being Mersenne - this method need privious checking number to be prime; public methods such as getNumber() for collecting number, closeDialog() for sending result to user and bunch of empty methods openDialog(), validateDialog() and virtual getRange() that accessible from main program. Some methods empty because they is overloads base non-virtual methods so main program will call base methods. */ class numberResearcher : public storage { // There is no need to share this containers with derrived class // and main program private: // messages represent as strings for number research dialogs std::string enterNumber = "\nYou entered number for research: "; std::string MersennePrime = "\nYou enter a Mersenne prime number.\n"; std::string notPrime = "\nIt's not a prime number.\n"; std::string justPrime = "\nIt's just a prime number, but not Mersenne((\n"; // integer container for collected number from user unsigned long long int number; // research method with bool return shared with range research class protected: // integer vector container for prime numbers for given length std::vector pVec; // bool container, true - prime number, false - not prime bool prime_status = false; // Method check if number is prime void checkPrime(unsigned long long int x){ // initial value of status - false - not prime prime_status = false; // prime number if ( x == 2 ){ prime_status = true; return; } // every even number are not prime if ( !(x % 2) ){ prime_status = false; return; } // divise with every odd number until find devisor, // time exceeded or numbers exceeded for (unsigned long long int i = 1; (2*i+1)<=(x/2); i++){ // in case finding devisor stop cycle if ( !( x % (2*i+1) ) ){ prime_status = false; return; } } // at this point every number is prime prime_status = true; return; }; // Method return true in case number being prime bool checkMNumber(unsigned long long int x){ // temporary double container with power needs to recieve inputed x // result will be whole in case Marsenne number double c = log(x+1)/log(2); // result will be true if to numbers equal return !((int)c-c); }; // Main program need this methods public: // Empty method for calling bace class openDialog() void openDialog(){} // Empty method for calling bace class validateInput() void validateDialog(){} // Method collect number from user void getNumber(){ std::cin >> number; pOL(enterNumber); pOL(number); pOL('.'); } // Prepared virtual empty method for collecting range for research virtual void getRange(){} // Method sends result to user void closeDialog(){ // Only here research method calls for this class //getPrimes(number); checkPrime(number); if (prime_status){ if (checkMNumber(number)) pOL(MersennePrime); else pOL(justPrime); } else pOL(notPrime); } }; /* Derrived class rangeResearcher contain: private method for operate with inherited checkPrime(), messages for user, containers for collecting range and vector for lab numbers in the range, clock_t variables for counting time; public methods such as getRange() for collecting number, closeDialog() for sending result to user and bunch of empty methods openDialog() and validateDialog() that accessible from main program. Some methods empty because they is overloads base non-virtual methods so main program will call base methods. */ class rangeResearcher : public numberResearcher { // There is no need to share this containers and methods with derrived // class and main program private: // messages represent as strings for range research dialogs std::string enterLrange = "\nYou enter first number in the range: "; std::string enterRrange = "\nYou enter last number in the range: "; std::string MersenneRange = "\nAll Mersenne primes in the given range ["; std::string back = "] are:\n\n{ "; std::string notMe = "\nNot a single Mersenne prime in the given range((\n"; // integer container for begin of range unsigned long long int lRange; // integer container for end of range unsigned long long int rRange; // integer vector container for all Mersenne prime numbers in the range std::vector mVec; // Method called operate() and keep Mersenne prime number void operate(unsigned long long int start, unsigned long long int end){ // temporary container keep new iteration of checked number unsigned long long int next = start; // calculate new "candidate" by Mersenne formula for (int i = log(start+1)/log(2); ; i++){ // next calculated number with power i next = pow(2,i) - 1; // break when end limit exceeded if ( next > end ) break; // need to check if this prime number checkPrime(next); // push Mersenne primes to vector until limit exceeded if ( prime_status && (next >= start) ) mVec.push_back(next); } } // Main program need this methods public: // Empty method for calling bace class openDialog() void openDialog(){} // Empty method for calling bace class validateInput() void validateDialog(){} // Method collect range from user void getRange(){ std::cin >> lRange; pOL(enterLrange); pOL(lRange); pOL('.'); std::cin >> rRange; pOL(enterRrange); pOL(rRange); pOL('.'); } // Method sends result to user void closeDialog(){ // research in the range starts here operate(lRange, rRange); // send empty result vector to user if (mVec.empty()) pOL(notMe); else { pOL(MersenneRange); pOL(lRange); pOL(','); pOL(' '); pOL(rRange); pOL(back); // printing by vector iterator in the for-loop for (std::vector::iterator it = mVec.begin(); it != mVec.end(); it++){ pOL(*it); pOL(' '); } pOL("}.\n"); } } }; // Main program starting point int main() { // Initiliazing pointer to base class storage *entry = new storage; // Initiliazing dialog with user entry -> openDialog(); // Initiliazing analisis of input from user entry -> validateDialog(); // single-number mode if ( (entry -> approved) && (entry -> mode) ) { // Initiliazing pointer to numberResearcher class storage *check = new numberResearcher; // Initiliazing collecting number from user check -> getNumber(); // Closing dialog with user check -> closeDialog(); } // range of the numbers mode if ( (entry -> approved) && !(entry -> mode) ) { // Initiliazing pointer to rangeResearcher class storage *check = new rangeResearcher; // Initiliazing collecting range from user check -> getRange(); // Closing dialog with user check -> closeDialog(); } // deleting base class pointer delete entry; return 0; }

[Challenge]: Mersenne prime numbers