#include #include /* Using stacks and queues to check if a string is a palindrome. Undoubtedly the 'hard way', as well as a really good workout */ struct node { char info; node* link; }; class stack { public: stack() {st=0;} ~stack(){st=0;} bool is_empty_stack(){return !st;} void pop(){ if (st) { node* temp = st; st = st->link; delete temp; }} void destroy_stack(){ for(;st;pop()); } void initialize_stack(){ destroy_stack(); } char top() { return st->info; } void push(char t_info){ if (!st) { st = new node; st->link = NULL; } else { node* temp = st; st = new node; st->link = temp; } st->info = t_info; } private: node *st; }; class queue { public: queue() {qf=qr=0;} ~queue(){qf=qr=0;} bool is_empty_queue(){return !qf;} void delete_queue(){ if(qf) { node* temp = qf; qf = qf->link; delete temp; }} void destroy_queue(){ for(;qf;delete_queue()); } void initialize_queue(){ destroy_queue(); } char front(){ return qf->info; } char back() { return qr->info; } void add_queue(char t_info){ if(!qf) { qf = qr = new node; qr->link = 0; } else { node* temp = qr; qr = new node; temp->link = qr; } qr->info = t_info; } private: node *qf, *qr; }; int main() { stack obj1; queue obj2; char tc; bool isP = true; std::string str = "A Toyota: Race fast safe car: a Toyota"; for (int i=0; i96&&tc<123) tc-=32; obj1.push(tc); obj2.add_queue(tc); } while (!obj1.is_empty_stack() && isP) { if(obj1.top()!=obj2.front()) isP=0; obj1.pop(); obj2.delete_queue(); } std::cout << "The input string is " << (isP?"":"not ") << "a palindrome."; return 0; }

Palindrome Checker (Stack && Queue)