Stack Reviewer - Data Structure and Algorithm

Stack

Abstract Data Type (ADT), commonly used in most programming languages.

Linear Data Structure

This structure is following LIFO principle

(LIFO) Last-in-First-out

The elements which is placed (inserted or added) last, is accessed first.

push()

Pushing (storing) an element on the stack

pop()

Removing (accessing) an element from the stack

peek()

This get the top data element of the stack, without removing it

isFull()

Check if stack is full

isEmpty()

check if stack is empty

int peek() {

return stack[top];

}

Algorithm of peek() function

bool isempthy() {

if (top == -1)

return true;

else

return false;

}

Algorithm of isfull() function

bool isfull() {

if (top == MAXSIZE)

return true;

else

return false;

}

Step 1 − Checks if the stack is full.

Step 2 − If the stack is full, produces an error and exit.

Step 3 − If the stack is not full, increments top to point next empty space.

Step 4 − Adds data element to the stack location, where top is pointing.

Step 5 − Returns success

Push Operation

void push (int data) {

if (!isFull()) {

top = top +1;

stack[top] = data;

}eslse {

printf (“Could not insert data, Stack is full.\n”);

}

}

Algorithm for PUSH Operation

 Step 1 − Checks if the stack is empty.

 Step 2 − If the stack is empty, produces an error and exit.

 Step 3 − If the stack is not empty, accesses the data element at which top is pointing.

 Step 4 − Decreases the value of top by 1.

 Step 5 − Returns success.

Pop Operation steps

int pop (int data) {

if (!isempty()){

data = stack [top];

top = top - 1;

return data;

} else {

printf (“Could not retrieve data, Stack is empty.\n”);

}

}

Algorithm for Pop Operation

 Functional call management in recursion

 Undo mechanism in text editors

 Syntax parsing in compilers

 Backtracking algorithms (ex. Solving Mazes)

Application of Stack

Simplicity, Efficiency, Last-in, First-out (LIFO), Limited memory usage

Advantages of Stack Data Structure

Limited Access, Potential for Overflow, Not suitable for random access, Limited Capacity

Disadvantages of Stack Data Structure