add stack

Author: mahyaret

Stack/stack

@@ -0,0 +1,87 @@
+#include <iostream>
+
+class Stack{
+  int _maxSize;
+  int _top;
+  int *_data;
+
+public:
+  Stack(int capacity)
+  {
+    _maxSize = capacity;
+    _top = -1;
+    _data = new int(_maxSize);
+  }
+
+  int size()
+  {
+    return _top+1;
+  }
+  
+  bool isEmpty()
+  {
+    return (_top == -1);
+  }
+  
+  bool isFull()
+  {
+    return (_top == _maxSize-1);
+  }
+  
+  void push(int datum)
+  {
+    if (isFull())
+      {
+	std::cout<<"The Stack is full!"<<std::endl;
+	return;
+      }
+    _data[++_top] = datum;
+  }
+  
+  int peek()
+  {
+    if (isEmpty())
+      {
+	std::cout<<"Stack is empty!"<<std::endl;
+	return 0;
+      }
+    return _data[_top];
+  }
+  int pop()
+  {
+    if(isEmpty())
+      {
+	std::cout<<"Nothing to pop!"<<std::endl;
+	return 0;
+      }
+    return _data[--_top];
+  }
+};
+
+
+int main()
+{
+  Stack* st = new Stack(5);
+
+  st->push(1);
+  st->push(2);
+  st->push(3);
+
+  std::cout<<"Top element is "<<st->peek()<<std::endl;
+  std::cout<<"Stack size is "<<st->size()<<std::endl;
+
+  st->pop();
+  st->pop();
+  st->pop();
+
+  if(st->isEmpty())
+    {
+      std::cout<<"Stack is empty"<<std::endl;
+    }
+  else
+    {
+      std::cout<<"Stack is not empty"<<std::endl;
+    }
+		       
+  return 0;
+}