stack data structure be like :1)STACK 2)STACK POINTER (points to top of stack) let's say stack starts from address AA1 and ends in KK1.initially stack pointer points to address (AA1-001)... ok now lets come to the operation isempty() if stack pointer points to (AA1-001) isfull() if stack pointer points to KK1 size() STACK POINTER - AA1 delete() pop STACK[STACK POINTER] and free[STACK POINTER] all of these operations take constant time