// FIGURE 14.2 : STACK.H // Stack Class-Template #include using namespace std; #ifndef STACK_H #define STACK_H template // define template of type class-template class Stack { public: // declare prototypes Stack(int=10); // default constructor (Stack default size is 10) // deconstructor ~Stack() { delete [] stackPtr; // dynamically deallocate internal memory occupied for Stack } // end ~Stack deconstructor bool push(const T &); // Push an element on the top of stack pointer bool pop(T &); // pop an element off the stack, LIFO mechanism // do checking if Stack is in empty condition using is- family C++ built-in function // pointer is pointing to constant memory-address bool isEmpty() const { return top == -1; } // end of member function isEmpty() // do checking if Stack pointer is full condition using is- family C++ built-in function //pointer is pointing to constant memory-address bool isFull() const { return top == size-1; } // end of function isFull() private: int size; // position of element in the stack pointer int top; // location of the top element; return -1 means Stack is empty T *stackPtr; // pointer to internal representation of the Stack }; // end-of class-template Stack int main() { Stack doubleStack(5); // instantiate object doubleStack contains of 5 type double element-values double doubleValue = 1.1; cout << "Pushing elements onto doubleStack\n"; // push 5 double-type values onto class Stack object's doubleStack while (doubleStack.push(doubleValue)) { cout << doubleValue << ' '; doubleValue += 1.1; } // end of while loop to push values cout << "\nStack is full. Cannot push 6th double value: " << doubleValue <<"\n\nPopping elements from doubleStack object:\n"; /* push values 1.1 2.2 3.3 4.4 5.5 (already push 5 doubles values) cannot push value double 6.6. receive alerts. Stack is full, cannot push the 6th value 6.6 pop elements from doubleStack */ while (doubleStack.pop(doubleValue)) cout << doubleValue<<' '; // single statement after while clause /* after the 5th from the top double value removed, now stack is empty. */ cout << "\nStack is empty. Cannot pop -1th double value \n"; Stack intStack; // define Stack class object without arguments: intStack contains integer values, default size is 10 int intValue = 1; cout << "\nPushing elements onto object intStack: \n"; // push 10 intgers values onto intStack while (intStack.push(intValue)) { cout << intValue++ << ' '; // give empty space as delimiter between element. } // end while loop cout << "\nStack is full. Cannot push the 11th int value: " << intValue <<"\n\nPopping elements from intStack: \n"; /* push ionteger values 1 2 3 4 5 6 7 8 9 10 (already push 10 integer values) cannot push 11th element integer value. receive alerts. Stack is full, cannot push the 11th integer value 11 pop elements from doubleStack */ // pop elements from intStack while (intStack.pop(intValue)) cout << intValue << ' '; cout << "\nStack is empty. Cannot pop" << endl; return 0; } // end of main program // Member functions definitions // Stack's template constructor template Stack :: Stack(int s) : size (s > 0 ? s : 10), // validate size is non-negative and not more than maximum stack size 10 top (-1), // Stack ititially empty condition stackPtr(new T[size]) // dynamically allocating memory-space which are going to occupied by stack elements { // empty body } // end-of Stack-template's constructor // push element onto Stack // if successful, return true; otherwise return false template bool Stack :: push(const T &pushValue) { if (!isFull()) // if stack is empty { stackPtr[++top] = pushValue; // place item on Stack return true; // push successfuly } // end-if // else return false; // push is unsuccessful } // end of member function template push // pop element off Stack // if successful, return true, otherwise return false template bool Stack :: pop(T &popValue) { if (!isEmpty()) { popValue = stackPtr[top--]; // remove item from the top of stack pointer return true; // pop successful } //end-if return false; // pop unsuccessful } // end of member function template pop #endif

Stack Pointer Class Template