1.

STACK USING ARRAY

#include<stdio.h>
#define MAX 4
int a[MAX],TOP=-1;
int push(int item)
{
if(TOP>(MAX-1))
{
printf("\nStack full");
return;
}
TOP++;
a[TOP]=item;
printf("\nPushed item %d",item);
}
int pop()
{
if(TOP<0)
{
printf("\nStack empty popping not possible");
return;
}
TOP--;
printf("\nPoped one item");
}
void main()
{
int choice,cont=1,i,item;
do
{
printf("\n1:PUSH\n2:POP\n3:DISPLAY\nEnter your choice");
scanf("%d",&choice);
switch(choice)
{
case 1:
printf("\nEnter the item to be pushed onto stack");
scanf("%d",&item);
push(item);
break;
case 2:
pop();
break;
case 3:
if(TOP==-1)
{
printf("\nStack empty");
break;
}

for(i=TOP;i>=0;i--)
printf("\n%d",a[i]);
break;
default :
printf("\nInvalid choice");
}
printf("\nDo you want to continue (1/2) ?");
scanf("%d",&cont);
}while(cont==1);
}

INPUT/OUTPUT
Pushed item 10
Do you want to continue (1/2) ?1
1:PUSH
2:POP
3:DISPLAY
Enter your choice3
10
5
Do you want to continue (1/2) ?1
1:PUSH
2:POP
3:DISPLAY
Enter your choice2
Poped one item
Do you want to continue (1/2) ?1
1:PUSH
2:POP
3:DISPLAY
Enter your choice2
Poped one item
Do you want to continue (1/2) ?1
1:PUSH
2:POP
3:DISPLAY
Enter your choice2
Stack empty popping not possible
Do you want to continue (1/2) ?2

2.QUEUE USING ARRAY

#include<stdio.h>
#define MAX 4
int q[MAX],FRONT=-1,REAR=-1;
int enq(int item)
{
if(REAR==MAX-1)
{
printf("\nQueue full");
return;
}
if(FRONT==-1)
FRONT=0;
REAR++;
q[REAR]=item;
printf("\nEnqueue operation successfull");
}
int deq()
{
if((FRONT==-1)||(FRONT>REAR))
{
printf("\nQueue is empty");
return;
}
else if(FRONT==REAR)
{
FRONT=-1;
REAR=-1;
}
else
FRONT++;
printf("\nDequeue operation succesfull");
}
void main()
{
int choice,item,i;
char cntn='y';
do
{
printf("\n1:ENQUEUE\n2:DEQUEUE\n3:DISPLAY\nPlease enter
your choice");
scanf("%d",&choice);

switch(choice)
{
case 1:
printf("\nEnter the item to be entered into queue");
scanf("%d",&item);
enq(item);
break;
case 2:
deq();
break;
case 3:
if((FRONT==-1)||(FRONT>REAR))
{
printf("\nQueue empty");
break;
}
for(i=FRONT;i<=REAR;i++)
printf("\t%d",q[i]);
break;
default:
printf("\nInvalid choice");
}
printf("\nDo you want to continue (y/n) ?");
scanf(" %c",&cntn);
}while(cntn=='y');
}

INPUT/OUTPUT
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter your choice1
Enter the item to be entered into queue 4
Enqueue operation successfull
Do you want to continue (y/n) ?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter your choice 1
Enter the item to be entered into queue 3

Enqueue operation successfull

Do you want to continue (y/n) ?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter your choice3
4
3
Do you want to continue (y/n) ?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter your choice2
Dequeue operation succesfull
Do you want to continue (y/n) ?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter your choice2
Dequeue operation succesfull
Do you want to continue (y/n) ?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter your choice3
Queue empty
Do you want to continue (y/n) ?n

3. STACK USING LINKEDLIST

#include<stdio.h>
#include<stdlib.h>
struct stack
{
int item;
struct stack *link;
} *TOP=NULL;
typedef struct stack s;
int push()
{
s *temp;
temp=(s *)malloc(sizeof(s));
printf("\nEnter the data");
scanf("%d",&temp->item);
temp->link=TOP;
TOP=temp;
printf("\nPush operation successfull");
return;
}
int pop()
{
s *temp;
if(TOP==NULL)
{
printf("\nStack empty");
return;
}
temp=TOP;
TOP=TOP->link;
free(temp);
}
int display()
{
s *temp;
if(TOP==NULL)
{
printf("\nStack empty");
return;
}
temp=TOP;
while(temp!=NULL)
{
printf("\n%d",temp->item);
temp=temp->link;
}
}

void main()
{
int choice;
char ch='y';
do
{
printf("\n1:PUSH\n2:POP\n3:DISPLAY\nPlease enter a choice");
scanf("%d",&choice);
switch(choice)
{
case 1:
push();
break;
case 2:
pop();
break;
case 3:
display();
break;
default :
printf("\nPlease enter a valid choice");
}
printf("\nDo you want to continue(y/n)?");
scanf(" %c",&ch);
}while(ch=='y');
}

INPUT/OUTPUT
1:PUSH
2:POP
3:DISPLAY
Please enter a choice1
Enter the data 12
Push operation successfull
Do you want to continue(y/n)?y
1:PUSH
2:POP
3:DISPLAY
Please enter a choice1
Enter the data 22

Push operation successfull

Do you want to continue(y/n)?y
1:PUSH
2:POP
3:DISPLAY
Please enter a choice3
22
12
Do you want to continue(y/n)?y
1:PUSH
2:POP
3:DISPLAY
Please enter a choice2
Do you want to continue(y/n)?y
1:PUSH
2:POP
3:DISPLAY
Please enter a choice 3
12
Do you want to continue(y/n)?y
1:PUSH
2:POP
3:DISPLAY
Please enter a choice2
Do you want to continue(y/n)?y
1:PUSH
2:POP
3:DISPLAY
Please enter a choice3
Stack empty
Do you want to continue(y/n)?n

4. QUEUE USING LINKEDLIST

#include<stdio.h>
#include<stdlib.h>
struct queue
{
int data;
struct queue *next;
} *FRONT=NULL,*REAR=NULL;
typedef struct queue q;
int enq()
{
q *temp;
temp=(q *)malloc(sizeof(q));
printf("\nEnter the item to be enqueued");
scanf("%d",&temp->data);
if((FRONT==NULL)&&(REAR==NULL))
{
FRONT=temp;
REAR=temp;
}
else
{
REAR->next=temp;
REAR=temp;
}
printf("\nEnqueue operation successfull");
return;
}
int deq()
{
q *temp;
if(FRONT==NULL)
{
printf("\nQueue empty dequeueing not possible");
return;
}
temp=FRONT;
if(FRONT==REAR)
{
FRONT=NULL;
REAR=NULL;
}
else
{
FRONT=FRONT->next;
}

printf("\nDequeue operation successfull");

free(temp);
}
int display()
{
q *temp;
if(FRONT==NULL)
{
printf("\nQueue empty");
return;
}
temp=FRONT;
while(temp!=NULL)
{
printf("\t%d",temp->data);
temp=temp->next;
}
return;
}
void main()
{
int choice;
char ch='y';
do
{
printf("\n1:ENQUEUE\n2:DEQUEUE\n3:DISPLAY\nPlease enter a
choice");
scanf("%d",&choice);
switch(choice)
{
case 1:
enq();
break;
case 2:
deq();
break;
case 3:
display();
break;
default :
printf("\nPlease enter a valid choice");
}
printf("\nDo you want to continue(y/n)?");
scanf(" %c",&ch);
}while(ch=='y');
}

INPUT/OUTPUT
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter a choice1
Enter the item to be enqueued 20
Enqueue operation successfull
Do you want to continue(y/n)?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter a choice1
Enter the item to be enqueued 10
Enqueue operation successfull
Do you want to continue(y/n)?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter a choice 3
20
10
Do you want to continue(y/n)?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter a choice 2
Dequeue operation successfull
Do you want to continue(y/n)?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter a choice2
Dequeue operation successfull
Do you want to continue(y/n)?y
1:ENQUEUE
2:DEQUEUE
3:DISPLAY
Please enter a choice3
Queue empty
Do you want to continue(y/n)?n

5. BINARY SEARCH
#include<stdio.h>
int a[100],cnt=0,n;
void binsrch(int a[],int beg,int end,int key)
{
int flag=0,mid,i;
while(beg<=end)
{
mid=(beg+end)/2;
if(key<a[mid])
end=mid-1;
else if(key>a[mid])
beg=mid+1;
else if(key==a[mid])
{
flag=1;
break;
}
}
if(flag==1)
printf("\n%d is found at %d in the sorted version of the entered
array",key,mid+1);
else
printf("\n%d is not found",key);
}
void main()
{
int i,j,a[100],key,temp;
printf("\nEnter the number of elements in the array");
scanf("%d",&n);
printf("\nEnter the elements of the array");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
for(i=0;i<n;i++)
for(j=0;j<n-1;j++)
if(a[j]>a[j+1])
{
temp=a[j];
a[j]=a[j+1];
a[j+1]=temp;
}
printf("\nThe sorted array is ");
for(i=0;i<n;i++)
printf(" %d ",a[i]);
printf("\nEnter the element to be searched");
scanf("%d",&key);
binsrch(a,0,n-1,key);
}

INPUT/OUTPUT
Enter the number of elements in the array 4
Enter the elements of the array
2143
The sorted array is 1 2 3 4
Enter the element to be searched 3
3 is found at 3 in the sorted version of the entered array

6. QUICKSORT
#include<stdio.h>
void qsrt(int a[],int left,int right)
{
int q;
if(right>left)
{
q=partin(a,left,right);
qsrt(a,left,q-1);
qsrt(a,q+1,right);
}
}
int partin(int a[],int left,int right)
{
int p,j,i,temp;
p=a[left];
i=left;
j=right+1;
for(;;)
{
while(a[++i]<p)
if(i>=right)
break;
while(a[--j]>p)
if(j<=left)
break;
if(i>=j)
break;
else
{
temp=a[i];
a[i]=a[j];
a[j]=temp;
}
}
if(i==left)
return j;
temp=a[left];
a[left]=a[j];
a[j]=temp;
return j;
}

int main()
{
int a[100],n,i;
printf("\nEnter the number of elements in the array");
scanf("%d",&n);
printf("\nEnter the array");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
qsrt(a,0,n-1);
printf("\nThe sorted array is");
for(i=0;i<n;i++)
printf(" %d ",a[i]);
return;
}

INPUT/OUTPUT
Enter the number of elements in the array 5
Enter the array 21 14 2 56 1
The sorted array is 1 2 14 21 56

7. MERGESORT
#include<stdio.h>
void merge(int [],int,int,int);
void mergsrt(int [],int,int);
void mergsrt(int a[],int low,int up)
{
int q;
if(low<up)
{
q=(up+low)/2;
mergsrt(a,low,q);
mergsrt(a,q+1,up);
merge(a,low,up,q);
}
}
void merge(int a[],int low,int up,int mid)
{
//printf("proc once");
int i,j,k,b[10];
i=low;
k=low;
j=mid+1;
while((i<=mid)&&(j<=up))
{
if(a[i]<=a[j])
b[k++]=a[i++];
else
b[k++]=a[j++];
}
while(i<=mid)
b[k++]=a[i++];
while(j<=up)
b[k++]=a[j++];
for(i=low;i<=up;i++)
{
a[i]=b[i];
//printf(" %d ",b[i]);
}
}

void main()
{
int i,n,a[10];
printf("\nEnter the number of elements in the array ");
scanf("%d",&n);
printf("\nEnter the array");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
mergsrt(a,0,n-1);
printf("\nThe sorted array is ");
for(i=0;i<n;i++)
printf("\t%d",a[i]);
}

INPUT/OUTPUT
Enter the number of elements in the array 5
Enter the array 4 5 6 1 3
The sorted array is

8. HEAPSORT

#include<stdio.h>
void heapify(int a[],int i,int m)
{
int l,r,max,temp;
if(i==0)
{
l=1;
r=2;
}
else
{
l=2*i;
r=2*i+1;
}
max=i;
if((l<=m)&&(a[l]>a[max]))
max=l;
if((r<=m)&&(a[r]>a[max]))
max=r;
if(max!=i)
{
temp=a[i];
a[i]=a[max];
a[max]=temp;
heapify(a,max,m);
}
}
int main()
{
int a[10],i,j,n,temp,new;
printf("\nEnter the number of elements in the array");
scanf("%d",&n);
new=n;
printf("\nEnter the elements to be sorted");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
while(n>0)
{
for(i=n/2;i>=0;i--)
heapify(a,i,n);
temp=a[0];
a[0]=a[n];
a[n]=temp;

n=n-1;
}
printf("\nThe sorted array is");
for(i=0;i<new;i++)
printf("\t%d",a[i]);
}

INPUT/OUTPUT
Enter the number of elements in the array 4
Enter the elements to be sorted 22 343 2 1
The sorted array is

22

343

9. INFIX TO POSTFIX

#include<stdio.h>
#include<string.h>
char stac[100];
int TOP=0;
int isp(char x)
{
if((x=='+')||(x=='-'))
return 2;
else if((x=='*')||(x=='/')||(x=='%'))
return 4;
else if(x=='^')
return 5;
else if(x=='(')
return 0;
else if(x==')')
return -1;
else
return 8;
}
int icp(char x)
{
if((x=='+')||(x=='-'))
return 1;
else if((x=='*')||(x=='/')||(x=='%'))
return 3;
else if(x=='^')
return 6;
else if(x=='(')
return 9;
else if(x==')')
return 0;
else
return 7;
}
void push(char x)
{
if(TOP>=99)
printf("\nStack overflow");
else
{
TOP++;
stac[TOP]=x;
}
}

void output(char x)
{
printf("%c",x);
}
char pop()
{
if(TOP==-1)
{
printf("\nError");
return;
}
else
return stac[TOP--];
}
void conv(char *inf)
{
int i=0;
char x,item;
while(inf[i]!='\0')
{
item=inf[i];
x=pop();
if(icp(item)==7)
{
push(x);
output(item);
}
else if(item==')')
{
while(x!='(')
{
output(x);
x=pop();
}
}
else if(isp(x)>=icp(item))
{
while(isp(x)>=icp(item))
{
output(x);
x=pop();
}
push(x);
push(item);
}

else if(isp(x)<icp(item))
{
push(x);
push(item);
}
else
printf("\nInvalid expression");
i++;
item=inf[i];
}
}
void main()
{
int i,b;
char inf[100],temp;
stac[0]='(';
printf("\nEnter the infix expression");
scanf("%s",inf);
b=strlen(inf);
for(i=0;inf[i]!='\0';i++);
i--;
inf[i+1]=')';
inf[i+2]='\0';
printf("\nThe Postfix expression is ");
conv(inf);
}

INPUT/OUTPUT
Enter the infix expression (A+B)^C-(D*E)/F
The Postfix expression is AB+C^DE*F/-

10. HASHING
#include<stdio.h>
#include<stdlib.h>
#define MAX 10
struct bucket
{
int data;
struct bucket *next;
}*t=NULL,*arr[MAX]={NULL},*p=NULL;
int hash(int x)
{
return x%7;
}
void insert()
{
int s,item;
printf("\nEnter the item to be inserted");
scanf("%d",&item);
if(search(item)==1)
printf("\nThe element has already been inserted");
else
{
s=hash(item);
t=(struct bucket *)malloc(sizeof(struct bucket));
arr[s];
t->data=item;
t->next=arr[s];
arr[s]=t;
}
}
void delete()
{
int s,item;
printf("\nEnter the element");
scanf("%d",&item);
s=search(item);
if(s==0)
printf("\nThe element id not found");
else
{
s=hash(item);
p=arr[s];

if(p->data==item)
{
arr[s]=p->next;
printf("\nElement found and deletion succesfull");
free(p);
}
else
{
while(p!=NULL)
{
t=p->next;
if(t->data==item)
{
p->next=t->next;
printf("\nElement found and deletion succesfull");
free(t);
break;
}
p=t;
t=t->next;
}
}
}
}
void display()
{
int i;
for(i=0;i<10;i++)
{
printf("\n%d->",i);
p=arr[i];
if(p==NULL)
printf("NULL");
else
{
t=arr[i];
while(t!=NULL)
{
printf("%d->",t->data);
t=t->next;
}
printf("NULL");
}
}
}

int search(int item)

{
int s;
s=hash(item);
p=arr[s];
if(p==NULL)
{
}
else
{
while(p!=NULL)
{
if(p->data==item)
return 1;
p=p->next;
}
}
return 0;
}
void main()
{
int s,choice,item;
char ch='y';
do
{
printf("\n1:INSERT\n2:DELETE\n3:SEARCH\n4:DISPLAY\n5:EXIT\nPlease enter
your choice");
scanf("%d",&choice);
switch(choice)
{
case 1:
insert();
break;
case 2:
delete();
break;
case 3:
printf("\n enter the element to be searched");
scanf("%d",&item);
s=search(item);
if(s==1)
printf("\nFound");
else
printf("\nNot found");
break;
case 4:

display();
break;
case 5:
exit(0);
break;
default:
printf("\nPlease enter a valid choice");
}
printf("\nDo you want to continue(y/n)");
scanf(" %c",&ch);
}while(3);
}

INPUT/OUTPUT

1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 1
Enter the item to be inserted 2
Do you want to continue(y/n) y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 1
Enter the item to be inserted 9
Do you want to continue(y/n)y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 4

0->NULL
1->NULL
2->9->2->NULL
3->NULL
4->NULL
5->NULL
6->NULL
7->NULL
8->NULL
9->NULL
Do you want to continue(y/n) y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 3
enter the element to be searched 4
Not found
Do you want to continue(y/n)y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 3
enter the element to be searched 2
Found
Do you want to continue(y/n) y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 2
Enter the element 9
Element found and deletion succesfull

Do you want to continue(y/n)y

1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 4
0->NULL
1->NULL
2->2->NULL
3->NULL
4->NULL
5->NULL
6->NULL
7->NULL
8->NULL
9->NULL
Do you want to continue(y/n)y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice2
Enter the element 2
Element found and deletion succesfull
Do you want to continue(y/n)y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 4
0->NULL
1->NULL
2->NULL
3->NULL
4->NULL
5->NULL
6->NULL
7->NULL
8->NULL
9->NULL

Do you want to continue(y/n)y

1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice3
enter the element to be searched 9
Not found
Do you want to continue(y/n) y
1:INSERT
2:DELETE
3:SEARCH
4:DISPLAY
5:EXIT
Please enter your choice 5