#include #include #include /* This is a program which provides a few sets of solutions which satisfies: a + b + c + d = limit where 'limit' is user-defined, e.g. Input 120, 3000, 15000, -100, etc. Have fun generating 'infinite' number of solutions for the equation :> */ struct set { int a, b, c, d; bool operator==(set obj2) { if (this->a == obj2.a && this->b == obj2.b && this->c == obj2.c && this->d == obj2.d) { return true; } return false; } }; template struct set_set { Type info; set_set *node_ptr; }; template class probability { public: probability() { first = last = NewNode = NULL; } ~probability() { first = last = NewNode = NULL; } bool has_duplicate(set obj) { set obj2; for (set_set *temp = first; temp != NULL; temp = temp->node_ptr) { obj2.a = temp->info.a; obj2.b = temp->info.b; obj2.c = temp->info.c; obj2.d = temp->info.d; if (obj == obj2) return true; } return false; } void insert_node(int limit) { set obj; do { obj.a = rand() % limit; obj.b = rand() % (limit - obj.a); obj.c = rand() % (limit - obj.a - obj.b); obj.d = limit - obj.a - obj.b - obj.c; } while (has_duplicate(obj)); NewNode = new set_set ; NewNode->info = obj; if (first == NULL) { first = last = NewNode; NewNode->node_ptr = NULL; } else { set_set *temp = last; last = NewNode; last->node_ptr = NULL; temp->node_ptr = last; } } void display_all() { for (set_set *temp = first; temp != NULL; temp = temp->node_ptr) { std::cout << "a = " << temp->info.a << std::endl; std::cout << "b = " << temp->info.b << std::endl; std::cout << "c = " << temp->info.c << std::endl; std::cout << "d = " << temp->info.d << std::endl << std::endl; } } private: set_set *first, *last, *NewNode; }; int main() { srand(time(0)); probability obj; int limit; std::cin >> limit; std::cout << "a + b + c + d = " << limit << " ?" << std::endl << std::endl; for (int i = 0; i < 10; i++) { obj.insert_node(limit); } obj.display_all(); return 0; }

4 Term Summation Expression