C Program Day-17
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Transcript of C Program Day-17
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Push and Pop Operation in a stack
Define Enqueue & Dequeue method in a Queue
Discuss LIFO Method
Discuss FIFO Method
Define Stack & Queue
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Stack : (Pushdown list)
It is a linear data structure. The insertion of element on to the stack
is called as PUSH operation, and deletion of element from the stack iscalled as POP operation.
Elements insertion or deletion can be done at one end. It follows
Last-In First-Out technique or LIFO technique.
Using TOP pointer Push or Pop operation is performed
Stack Related Terms :
Top : This pointer points to the top most element of the stack. The top of
the stack indicates its door from where elements are entered or deleted.
It is used to verify stacks current position.
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Stack Underflow : When there is no element in the stack, the status of the stack is
known as Stack Underflow. The TOP is present at the bottom of the stack.
Stack Overflow : When the stack contains equal number of elements as per its
capacity and no more elements can be added, the status of stack is known as Stack
Overflow. In such position, the TOP rests at the highest position.
Storage : The capacity of the stack is known as Storage.
Representation of Stack : The stack is represented in various ways. The stack can be
shown as completely empty or fully filled or filled with few elements.
When stack has no elements, it is called as Empty Stack.
The stack with completely filled elements is called as Filled Stack, and no further
elements can be inserted.
A top pointer maintains track of the top elements of the stack. For empty stack, top
value is zero.
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When stack has one element the value of top is one. Whenever an element is
inserted in the stack the value of top is incremented by one (PUSH Operation)
In the same manner, the value of top is reduced by one when an element is
deleted from the stack (POP operation).
The push operation can be applied to any stack, but before applying pop
operation on the stack.
Stack Implementation :
(i) Static Implementation : It can be achieved using arrays. Once a size of an
array is declared, its size cannot be modified during execution. It is also
inefficient for utilization of memory. It cannot be expanded, when we store
more elements. The vacant space of stack is wasted, when we store less
elements.
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(ii) Dynamic Implementation : Pointer can be used for implementation of
stack. The link list is an example of this implementation. Using this
implementation at runtime, there is no restriction on the number of
elements. The stack may be expandable. Memory is efficiently utilized
with pointers
Operation on stack :
The following fundamental operations on stack can be carried outthrough static implementation called array implementation.
(i) creating a stack
(ii) Checking stack either full or empty
(iii) Initializing a stack
(iv) Insert (PUSH) an element into the stack
(v) Delete (POP) an element from the stack
(vi) Display elements of stack.
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Stack using Pointer : Pointer implementation of a stack can be carried out is
similar to array implementation. This Dynamic Implementation, create
NODE at run time, accordingly PUSH, POP operation can be done.
(i) creating a stack
(ii) Checking stack either full or empty
(iii) Initializing a stack
(iv) Insert (PUSH) an element into the stack
(v) Delete (POP) an element from the stack
(vi) Display elements of stack.
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#include
struct stacktype
{
int item[100];
int top;
};struct stacktype stack;
int givendata,poppeddata;
int choice;
isstackfull()
{if (stack.top == 100)
return 1;
else
return 0;
}
isstackempty(){
if (stack.top == 0)
return 1;
else
return 0;
}Continued
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void createstack()
{
stack.top = 0;
}
void push()
{
stack.top = stack.top +1;
stack.item[stack.top] = givendata;
}
void pop()
{
poppeddata = stack.item[stack.top];
stack.top= stack.top -1;
}
void main()
{
clrscr();
createstack(stack);Continued,
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do
{
printf("\n1. Push");
printf("\n2. Pop");
printf("\n3. Show Top");
printf("\n4. Quit\n");
printf("\n Enter your Choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:printf("\nEnter data to push : ");
scanf("%d",&givendata);
if (isstackfull(stack))
printf("\nStack Full!!!,cannot push");
elsepush();
printf("Data pushed into stack\n");
break;case 2:
if (isstackempty(stack)== 1)
Continued,
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printf("\nStack Empty\n");
else
{
pop();
printf("\nData popped is %d\n",poppeddata);
}
break;
case 3:
if (isstackempty()== 1)
printf("\nStack empty\n");
elseprintf("\nTop most item is %d\n",stack.item[stack.top]);
break;
}
}while(choice != 4);
}
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# include
# include
#define null 0
struct list
{
int item;
struct list *next;
};
typedef struct list node;node *start,*temp;
void push()
{
node *new,*temp;int newitem;
while(1) {
printf("\nEnter new integer data [0 to exit]:");
scanf("%d",&newitem);
Continued,
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if (newitem ==0)
break;
new = (node *)malloc(sizeof(node));
new->item = newitem;
new->next = start;
start = new;
}
}
void display()
{node *temp;
temp = start;
if (start == null)
printf("\nEmpty Stack");
elsewhile(temp)
{
printf("%d ",temp->item);
temp = temp->next;
}
} Continued,
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void pop()
{
node *temp;
if (start == null)
printf("\n Empty Stack");
else {
printf("\n Popped item is %d",start->item);
temp = start->next;
free(start);
start = temp;
}}void main()
{
int choice;
start = null;
clrscr();do{
printf("\n 1. Push");
printf("\n 2. Pop");
printf("\n 3. Display");
Continued,
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printf("\n 4. Exit");
printf("\n Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{case 1:
push();
break;
case 2:
pop();break;
case 3:
display();
break;
}
}while(choice != 4);
}
