The following program will read in a character string, copy it to a character array, enqueue and push the characters into a stack, and then dequeue and pop the stack to compare the letters. The point is to determine whether or not the word is a palindrome.
The code debugs just fine and brings up the command prompt like it should. However, when I enter a word, the command prompt proceeds past the comparison and asks for another word to enter without displaying whether or not the word is a palindrome.
The code is below, and the class files are at the bottom. Can someone tell me what's wrong?
Code:#include <iostream>#include <string> #include "queue.h" #include "stack.h" using namespace std; int main() { string z; int y = 0; char x[20]; stack a; queue b; cout << "Please enter a word below to test whether or not it is a palindrome." << endl; cout << "This program will both push the characters into a stack and enqueue the" << endl << "characters, and then pop/dequeue respectively to compare letters." << endl << endl; cout << "If you would like to quit at any time, enter 'Q'." << endl << endl; cout <<"Please enter a word to be tested: "; cin >> z; x[0] = NULL; while (x[0] != 'Q') { y = 0; while (x[y] != NULL) { x[y] = z[y]; a.stack::push(x[y]); b.queue::enqueue(x[y]); x[y] = NULL; y++; } while (!a.isEmpty()) { while (!b.isEmpty()) { char c, d; while (y >= 0) { a.pop(c); b.dequeue(d); if (c != d) { cout << "That word is not a palindrome." << endl << endl; goto exit; } else if (y == 0 && c == d) cout << "That word is a palindrome." << endl << endl; else y--; } } } exit: cout << "If you would like to run the function again, enter a word to be tested." << endl; cout << "Otherwise, enter 'Q' to quit." << endl << endl; cout << "Please enter a command: "; cin >> x; } system("pause"); return 0; } stack::stack(void) { top = NULL; } stack::~stack(void) { } queue::queue(void) { front = NULL; } queue::~queue(void) { } void stack::push(char x) { Node *temp; temp = new Node; // create a new node to hold the item to be pushed temp->item = x; // store the item temp->next = top; // link the node into the list top = temp; // adjust the top pointer } void stack::pop(char &x) { if (!isEmpty()) { x = top->item; // send the top item by reference Node *temp; temp = top; // set a temporary pointer to top top = top->next; // move the top pointer to new top position delete temp; // delete the node that was popped } } void queue::enqueue(char x) { Node *temp; temp = new Node; // create a new node to hold the item to be pushed temp->item = x; // store the item if (front == NULL) front = temp; else temp->next = back; // link the node into the list back = temp; // adjust the back pointer } void queue::dequeue(char &x) { if (!isEmpty()) { x = front->item; // send the front item by reference Node *temp; temp = front; // set a temporary pointer to front front = front->next; // move the front pointer to new front position delete temp; // delete the node that was dequeued } } bool stack::isEmpty() { return (top == NULL); } bool queue::isEmpty() { return (front == NULL); } #pragma once class stack { private: struct Node { char item; Node *next; }; Node *top; public: // Constructor & Destructor stack(void); ~stack(void); // Member functions void push(char x); void pop(char &x); bool isEmpty(); }; #pragma once class queue { private: struct Node { char item; Node *next; }; Node *front; Node *back; public: // Constructor and Destructor queue(void); ~queue(void); // Member functions void enqueue(char x); void dequeue(char &x); bool isEmpty(); };
Originally Posted by Adak
