Add a simple class stack, and example

data_structure/stk/stack.cpp

@@ -0,0 +1,114 @@
+#include <iostream>
+#include <assert.h>
+#include "stack.h"
+
+using namespace std;
+
+/* Default constructor*/
+template <class Type>
+stack<Type>::stack()
+{
+    stackTop = NULL;
+    size = 0;
+}
+
+/* Destructor */
+template <class Type>
+stack<Type>::~stack()
+{
+}
+
+/* Display for testing */
+template <class Type>
+void stack<Type>::display()
+{
+    node<Type> *current = stackTop;
+    cout << "Top --> ";
+    while(current != NULL) {
+        cout<<current->data<< "  ";
+        current = current -> next;
+    }
+    cout <<endl;
+    cout << "Size of stack: " << size << endl;
+}
+
+/* Determine whether the stack is empty */
+template <class Type>
+bool stack<Type>::isEmptyStack()
+{
+    return (stackTop == NULL);
+}
+
+/* Clear stack */
+template <class Type>
+void stack<Type>::clear()
+{
+    stackTop = NULL;
+}
+
+/* Add new item to the stack */
+template <class Type>
+void stack<Type>::push(Type item)
+{
+    node<Type> *newNode;
+    newNode = new node<Type>;
+    newNode->data = item;
+    newNode->next = stackTop;
+    stackTop = newNode;
+    size++;
+}
+
+/* Return the top element of the stack */
+template <class Type>
+Type stack<Type>::top()
+{
+    assert(stackTop != NULL);
+    return stackTop->data;
+}
+
+/* Remove the top element of the stack */
+template <class Type>
+void stack<Type>::pop()
+{
+    node<Type> *temp;
+    if(!isEmptyStack()) {
+        temp = stackTop;
+        stackTop = stackTop->next;
+        delete temp;
+        size--;
+    } else {
+        cout << "Stack is empty !" << endl;
+    }
+}
+
+/* Operator "=" */
+template <class Type>
+stack<Type> stack<Type>::operator=(stack<Type> & otherStack)
+{
+    node<Type> *newNode, *current, *last;
+
+    if (stackTop != NULL) /* If stack is no empty, make it empty */
+        stackTop = NULL;
+    if (otherStack.stackTop == NULL)
+        stackTop = NULL;
+    else {
+        current = otherStack.stackTop;
+        stackTop = new node<Type>;
+        stackTop->data = current->data;
+        stackTop->next = NULL;
+        last = stackTop;
+        current = current ->next;
+        /* Copy the remaining stack */
+        while (current != NULL)
+        {
+            newNode = new node<Type>;
+            newNode->data = current->data;
+            newNode->next = NULL;
+            last->next = newNode;
+            last = newNode;
+            current = current->next;
+        }
+    }
+    size = otherStack.size;
+    return *this;
+}