Stack Brush Up And Basic Programming Technique

A stack is a container of objects that are inserted and removed according to the last-in first-out (LIFO) principle.A stack is a limited access data structure - elements can be added and removed from the stack only at the top. push adds an item to the top of the stack, pop removes the item from the top. A helpful analogy is to think of a stack of books; you can remove only the top book, also you can add a new book on the top.





Primary operations defined on a stack:
PUSH : add an element at the top of the list.
POP    : remove the at the top of the list.
Also "IsEmpty()" and IsFull" function, which tests whether a stack is empty or full respectively.

Example :
Practical Example :Think of piles of books kept in a vertical box.
Computer World: During subroutine call.

Application of Stack : 
1. Solving Arithmetic Expression.
2. Solving Tower of Hanoi.
3. Reverse a String .
4 Conversion of a infix expression into prefix expression.

Algorithm of the Push Operation :

Push(item,array,n,top)
{
if(n>=top)
print   "The stack is full".
else 
{
top=top+1;
array[top]=item;
}
}

Visualization of Push Operation :
Algorithm of the Pop Operation :

Pop(item,array,top)
{
if (top<0)
The print "stack is empty"
else
{
item =array[top];
top=top+1;
}
}

This is all about the basics of Stack . Now we will do some programming in other post and then complex programming.

Please comment if you find any mistake.