/* Example of using discrete_distribution to generate a random number based on probabilty This example returns a number based on the following chances (distributions) // 1-5: 75% // 6-8: 20% // 9-10 5% As you can see, being lucky is hard! If you like this give us a like */ #include #include unsigned long long rdtsc() { unsigned int lo, hi; __asm__ __volatile__("rdtsc" : "=a" (lo), "=d" (hi)); return ((unsigned long long)hi << 32) | lo;} /* __________________START: RANDOM NUMBER GENERATION ______________________ */ class randomNum { public: randomNum(); int returnUniform(int minRange, int maxRange); int returnDiscrete(); private: std::random_device rd; typedef std::mt19937_64 MyGen; MyGen gen; }; randomNum::randomNum(): gen(rd()) { gen.seed(rdtsc()); } int randomNum::returnUniform(int minRange, int maxRange) { std::uniform_int_distribution dist { minRange, maxRange }; return dist(gen); } int randomNum::returnDiscrete() { //return random number with lower ranged numbers being more likely // i.e change range dependant on results of discrete distribution // break up of 1-10 is: // 1-5: 75% // 6-8: 20% // 9-10 5% std::discrete_distribution dist{ 0.75, 0.20, 0.05 }; // select which min and max values based on probability switch (dist(gen)) { case 0: return returnUniform(1, 5); // return between 1 and 5 case 1: // return between 6 and 8 return returnUniform(6, 8); case 2: // return between 9 and 10 return returnUniform(9,10); } } /*____________________ END: RANDOM NUMBER GENERATION CLASS __________________ */ int main() { randomNum randomNumber; std::cout << "Generating a random luck stat between 1-10" << std::endl; int theNumber = randomNumber.returnDiscrete(); switch(theNumber) { case 1 ... 5: std::cout << "You got " << theNumber << std::endl << "You are not very lucky. Better luck next time"; break; case 6 ... 8: std::cout << "You got " << theNumber << std::endl << "Your pretty lucky! Maybe you can get 10 next time?"; break; case 9 ... 10: std::cout << "You got " << theNumber << std::endl << "WOW! You have all the luck! Go buy a lottery ticket!"; break; } return 0; }

Random - Discrete Distribution - How lucky are you?