// Input - Upper limit, U, to generate // random number between. // Output - Random Number between [1,U]. // Whats so new in new_rand : // 0) Uniform distribution - // Outputs are no longer consecutive. // 1) C++11 Support - // Works great on modern compilers. // 2) chrono's system seed - // Accurate to the smallest tick. // 3) Template Overloads - // Can return a char, int, or float. // 4) Optional Range Parameters // User can choose between old and new. #include #include #include // RAND_MAX #include #include //random_engine, distribution using namespace std; using namespace chrono; typedef uniform_int_distribution uid; typedef uniform_real_distribution urd; unsigned myseed; default_random_engine time_seed; uid intrand (0,RAND_MAX); urd realrand (0,static_cast(RAND_MAX)); void snew_rand() { myseed = system_clock::now(). time_since_epoch().count(); time_seed.seed(myseed); } template T new_rand (T L=0,T U=RAND_MAX) // A better random function. { decltype(typeid(T)) v = typeid(T); if(v==typeid(float)||v==typeid(double)) { urd::param_type nr(L,U); realrand.param(nr); return realrand(time_seed); } else if(v==typeid(char)) { if(U>char(255)||U==RAND_MAX) U=255; uid::param_type nr(L,U); intrand.param(nr); return char(intrand(time_seed)); } else { uid::param_type nr(L,U); intrand.param(nr); return intrand(time_seed); } } int main() { snew_rand(); // Sets time seed for new_rand. int UR; cin>>UR; for(int i=0;i<10;i++) cout<<1+new_rand()%UR<(1,UR); }

Challenge - Random Number Generator