Data Structures in C

#include<stdio.h>

#include<stdlib.h>

#include<conio.h>

#include<malloc.h>

struct link

{

int num;

struct link *next;

};

typedef struct link node;

node *startnode;

int n,i;

int flag=0;

void main()

{

int ch;

void create();

void insert();

void del();

void disp();

clrscr();

while(1)

{

printf(“\n 1. Create List”);

printf(“\n 2. Delete Node”);

printf(“\n 3. Insert Node”);

printf(“\n 4. Display”);

printf(“\n 5. Exit”);

printf(“\n Enter your choice:”);

scanf(“%d”,&ch);

switch(ch)

{

case 1:

create();

break;

case 2:

del();

break;

case 3:

insert();

break;

case 4:

disp();

break;

case 5:

exit(0);

}

}

}

void create()

{

node *curnode;

startnode=malloc(sizeof(node *));

flag=1;

printf(“Enter the total no in the list:”);

scanf(“%d”,&n);

printf(“Enter the number:”);

scanf(“%d”,&startnode->num);

startnode->next=malloc(sizeof(node *));

curnode=startnode;

for(i=1;i<n;i++)

{

curnode=curnode->next;

printf(“Enter the number:”);

scanf(“%d”,&curnode->num);

curnode->next=malloc(sizeof(node *));

}

}

void disp()

{

int i;

struct link *cnode;

cnode=startnode;

if(flag==0)

printf(“\n List is empty\n”);

else

{

for(i=0;i<n;i++)

{

printf(“%d\n”,cnode->num);

cnode=cnode->next;

}

}

printf(“\n *****************************\n”);

}

void del()

{

int i,p;

node *curnode,*temp;

if(flag==0)

printf(“List is empty”);

else

{

printf(“Enter the position”);

scanf(“%d”,&p);

curnode=startnode;

if(p>n)

printf(“Enter the correct position:”);

else if(p==1)

{

if(p==n)

flag=0;

startnode=curnode->next;

free(curnode);

printf(“\n Node is deleted”);

n=n-1;

}

else

{

for(i=1;i<p-1;i++)

curnode=curnode->next;

temp=curnode->next;

curnode->next=temp->next;

free(temp);

printf(“Node is deleted”);

n=n-1;

}

}

}

void insert()

{

int i,p;

node *newnode,*curnode,*temp;

newnode=malloc(sizeof(node *));

if(flag=0)

printf(“List is empty”);

else

{

printf(“Enter the number:”);

scanf(“%d”,&newnode->num);

printf(“Enter the position:”);

scanf(“%d”,&p);

curnode=startnode;

if(p>n+1)

printf(“Enter the correct position:”);

else if(p==1)

{

newnode->next=startnode;

startnode=newnode;

printf(“\n Node is inserted”);

n=n+1;

}

else

{

for(i=1;i<p-1;i++)

curnode=curnode->next;

temp=curnode->next;

curnode->next=newnode;

newnode->next=temp;

printf(“Node is inserted”);

n=n+1;

}

}

getch();

}