Doubly list

DOUBLY LINKED LIST

1.   Design a doubly linked list to represent sparse matrix. Each node in the list can have the row and column index of the matrix element and the value of the element

//Program starts here

#include<stdio.h>

#include<stdlib.h>

struct node{

     int data;

     int row,col;

     struct node *next;

     struct node *prev;

};

typedef struct node snode;

snode *f=NULL,*l=NULL,*p,*new;

snode *l1=NULL;

snode *insert(snode *f,int x,int r, int c)

{

     new=malloc(sizeof(snode));

     new->data=x;

     new->col=c;

     new->row=r;

     new->next=new->prev=NULL;

     if(f==NULL)

     {

          f=new;

     }

     else

     {

          p=f;

          while(p->next!=NULL)

              p=p->next;

          p->next=new;

          new->prev=p;

     }

     return f;

}

int main()

{

     snode *tmp;

     int data,i,j,r,c,flag;

     int r1,c1;

     printf("matrix row and column\n");

     scanf("%d",&r);

     scanf("%d",&c);

     printf("enter mattrix data\n");

     for(i=0;i<r;i++)

     {

          for(j=0;j<c;j++)

          {

              r1=i+1;

              c1=j+1;

              printf(" \nrow %d  and  column %d :\n",r1,c1);

              scanf("%d",&data);

              if(data!=0)

                   l1=insert(l1,data,i,j);

          }

     }

     for(i=0;i<r;i++)

     {

          for(j=0;j<c;j++)

          {

              tmp=l1;

              flag=0;

              while(tmp!=NULL)

              {

                   if((tmp->row==i) && (tmp->col==j))

                   {

                        printf("%d\t",tmp->data);

                        flag=1;

                        break;

                   }

                   tmp=tmp->next;

              }

              if(flag!=1)

              {

                   printf("%d\t",0);

              }

          }

          printf("\n");

     }

}