////////////////////////////////////////////////////////////////// //////**************CHALLENGE: Josephus Problem //////****************Author: Petros Simidyan ////***************** #include struct People { bool *isAlife; int size; People(const int& size=20) { this->size = size; isAlife = new bool[size]; for (int i = 0; i < size; i++) isAlife[i] = true; } ~People() { delete[]isAlife; } bool operator[](const int& index) const { if (index < 0 || index >= size) { std::cerr << "Index out of bound!" << std::endl; std::cin.get(); } return isAlife[index]; } void kill(const int& killer, const int& victim) const { std::cout << "The " << killer+1 << ". person kills " << victim+1 << ". person!" << std::endl; isAlife[victim] = false; } void giveSword(const int& killer) const { std::cout << "The " << killer+1 << ". person receives the sword!" << std::endl; } }; //this function does all work: p is the list of persons, killer is the index of the person who has sword //curPerson means current person is just the current index, counter is the number of persons, who are alife void josephus(const People& p, const int& killer, const int& curPerson, const int& counter) { //if current person is out of range the function should start with index 0 if(curPerson>=p.size) return josephus(p, curPerson, curPerson%p.size, counter); //if the killer index<0 means that there is no killer with sowrd //the function give the killer the current person index, only if the person is not dead if (killer < 0 && p[curPerson]) { p.giveSword(curPerson); return josephus(p, curPerson, curPerson + 1, counter); } //function have killer and the current person is alife //function kills current person and decrease the counter if (p[curPerson]) { p.kill(killer, curPerson); //counter=2 means, that only killer is alife //the function prints the name of last person //who is alife, in this case- killer if (counter == 2) { std::cout << "The only alife person is " << killer << std::endl; return; } return josephus(p, -1, curPerson + 1, counter - 1); } else //currentperson is already dead, so function skips it return josephus(p, killer, curPerson + 1, counter); } int main() { People p(25); josephus(p, 0, 1, p.size); std::cin.get(); return 0; }