Procedure: PUSH (S, TOP, X)
- This procedure inserts an element X to the top of a stack.
- Stack is represented by a vector S containing N elements.
- A pointer TOP represents the top element in the stack.
1. [Check for stack overflow]
If TOP = N
Then write (‘STACK OVERFLOW’)
Return
2. [Increment TOP]
TOP ? TOP + 1
3. [Insert Element]
S[TOP] ? X
4. [Finished]
Return
Function: POP (S, TOP)
- This function removes & returns the top element from a stack.
- Stack is represented by a vector S containing N elements.
- A pointer TOP represents the top element in the stack.
1. [Check for Stack underflow]
If TOP = 0
Then Write (‘STACK UNDERFLOW ON POP’)
Return(0)
2. [Decrement TOP Pointer]
TOP ? TOP - 1
3. [Return former top element of stack]
Return (S[TOP + 1])
