C Programming Code Examples

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Linked List implementation



Linked List implementation

#include"m_list.h"

void main()
   {
      list *first=NULL,*second=NULL,*third=NULL;
      int choice,i;
      char ch='y';
      while(1)
    {
        clrscr();
        printf("
     case 1:  Create list");
        printf("
     case 2:  Add in the list");
        printf("
     case 3:  Delete in the list");
        printf("
     case 4:  Append two list");
        printf("
     case 5:  show list");
        printf("
     case 6:  Exit");
        printf("
     Enter your choice : ");
        scanf("%d",&choice);
        switch(choice)
      {
         case 1:    //create list
            while(ch!='n')
              {
            printf("
Enter element : ");
            scanf("%d",&i);
            create(&first,i);
            printf("
Enter element (y/n) : ");
            fflush(stdin);
            scanf("%c",&ch);
              }
         break;
         case 2:   //add in the list
              int c;
              clrscr();
              printf("
     case 1:  Add in Beginning");
              printf("
     case 2:  Add in End");
              printf("
     case 3:  Add After a given element");
              printf("
     case 4:  Return to main menu");
              printf("
     Enter your choice : ");
              scanf("%d",&c);
              switch(c)
             {
                case 1: add_at_beg(&first);
                   break;
                case 2: add_at_end(&first);
                   break;
                case 3: add_after_given_element(&first);
                   break;
                case 4: break;
             }
         break;
         case 3:
              clrscr();
              printf("
     case 1:  Delete in Beginning");
              printf("
     case 2:  Delete in End");
              printf("
     case 3:  Delete a specified element");
              printf("
     case 4:  Return to main menu");
              printf("
     Enter your choice : ");
              scanf("%d",&c);
              switch(c)
             {
                case 1: del_at_beg(&first);
                   break;
                case 2: del_at_end(&first);
                   break;
                case 3: del_specified_element(&first);
                   break;
                case 4: break;
             }
         break;
         case 4:
               char ch='y';
               printf("Enter element in second list : ");
               while(ch!='n')
               {
                  printf("
Enter element : ");
                  scanf("%d",&i);
                  create(&second,i);
                  printf("
Enter element (y/n) : ");
                  fflush(stdin);
                  scanf("%c",&ch);
               }
               append(&third,first,second);

         break;
         case 5:    //show list
              clrscr();
              printf("
     case 1:  List 1");
              printf("
     case 2:  List 2");
              printf("
     case 3:  List 3");
              printf("
     Enter choice : ");
              scanf("%d",&choice);
              switch(choice)
             {
                case 1: show(first);break;
                case 2: show(second);break;
                case 3: show(third);break;
            }
         break;
         case 6:    exit(0);

      }


    }
   }



#include<conio.h>
#include<stdio.h>
#include<alloc.h>
#include<stdlib.h>
typedef struct list
  {
     int info;
     struct list *next;
  };

//.................Function Declaration ...........

void create(struct list **p,int i)
   {
      struct list *temp,*q=*p;
      temp=(struct list*)malloc(sizeof(struct list));
      temp->info=i;
      temp->next=NULL;
      if(*p==NULL)
      *p=temp;
      else
   {
      while(q->next!=NULL)
        q=q->next;
      q->next=temp;
   }
   }
int append(struct list **t,struct list *f,struct list *s)
   {
   struct list *temp=*t;
   if(f==NULL && s==NULL)
      return 0;
   while(f)
     {
       create(t,f->info);
       f=f->next;
     }
   while(s)
     {
       create(t,s->info);
       s=s->next;
     }

   return 0;
   }
void show(struct list *p)
   {
     if(p==NULL)
   printf(" List is Empty");
     else
     while(p)
       {
    printf("%d  ",p->info);
    p=p->next;
       }
     getch();
   }
void add_at_beg(struct list **l)
     {
      struct list *temp=(struct list *)malloc(sizeof(struct list));
      printf("
Enter element : ");
      scanf("%d",&temp->info);
      temp->next=NULL;
      if(*l==NULL)
         *l=temp;
      else
         {
       temp->next=*l;
       *l=temp;
         }
     }
void del_at_beg(struct list **l)
     {
      list *temp;
      if(*l==NULL)
         {
      printf("
List is empty");
      getch();
         }
      else
         {
      temp=*l;
      *l=(*l)->next;
      free(temp);
         }
     }
void add_at_end(struct list **l)
       {
        list *temp,*p;
        temp=(struct list *)malloc(sizeof(struct list));
        printf("
Enter element : ");
        scanf("%d",&temp->info);
        temp->next=NULL;
        if(*l==NULL)
      *l=temp;
        else
       {
         p=*l;
         while(p->next!=NULL)
            p=p->next;
         p->next=temp;
       }
       }

void del_at_end(struct list **l)
       {
        list *temp,*p;
        if(*l==NULL)
      {
        printf("
List is Empty");
        getch();
      }
        else if((*l)->next==NULL)
       {
          temp=*l;
          *l=NULL;
          free(temp);
       }
        else
       {
         p=*l;
         while(p->next->next!=NULL)
            p=p->next;
         temp=p->next->next;
         p->next=NULL;
         free(temp);
       }
       }
void add_after_given_element(list **l)
    {
       list *temp,*p;
       int m;
       temp=(struct list *)malloc(sizeof(struct list));
       printf("
Enter element : ");
       scanf("%d",&temp->info);
       printf("
Enter position after which element inserted  : ");
       scanf("%d",&m);
       temp->next=NULL;
       if(*l==NULL)
   *l=temp;
       else
    {
      p=*l;
      while(p->next!=NULL)
         if(p->info==m)
      break;
         else
      p=p->next;

      temp->next=p->next;
      p->next=temp;

    }
    }
void del_specified_element(list **l)
    {
       list *temp,*p,*q;
       int m;
       printf("
Enter element which is deleted : ");
       scanf("%d",&m);
       if(*l==NULL)
     {
       printf("
List is Empty");
       getch();
     }
       else if((*l)->next!=NULL && (*l)->info==m)
     {
         temp=*l;
         *l=(*l)->next;
         free(temp);
     }
       else if((*l)->next==NULL && (*l)->info==m)
      {
         temp=*l;
         *l=NULL;
         free(temp);
      }
       else
    {
      p=*l;
      while(p!=NULL)
         if(p->info==m)
       break;
         else
       {
         q=p;
         p=p->next;
       }
      temp=p;
      q->next=p->next;
      free(temp);
    }
    }