// readlines: read lines; update in buffer
int readlines(char *lptr[], int bufsize, int *pos) {
if (bufsize == 0)
return 0;
int nlines = 0, len, lastlen = 0;
char temp[MAXLEN], *p, **st = lptr;
*pos = 0;
while ((len = getlinef(temp,MAXLEN)) > 0) {
if (lastlen > 0) {
adelete(*lptr, lastlen);
while (lptr < st + bufsize)
*lptr++ -= lastlen;
lptr = st;
lastlen = 0;
}
if ((p = alloc(len)) == NULL) {
printf("Out of storage.\n");
return nlines;
} else {
temp[len-1] = '\0'; // delete newline
strcpy(*lptr = p, temp);
*pos = lptr - st;
lptr = st + (1+lptr-st)%bufsize;
if (lptr - st == 0)
lastlen = len;
nlines = (nlines >= bufsize) ? bufsize : nlines+1;
}
}
return nlines;
}
void main()
{
int n,num,num1,flag=0;
while(1)
{
clrscr();
printf("\n\t\t****** DOUBLY LINKED LIST OPERATION ******\n");
printf("\t\t......______________________________......\n");
printf("\nWELCOME,WHAT YOU WANT TO DO ?::");
printf("\n_____________________________\n\n");
printf("\nINSERTION --PRESS 1\n");
printf("\nDELETION --PRESS 2\n");
printf("\nSEARCH --PRESS 3\n");
printf("\nCOUNT --PRESS 4\n");
printf("\nDISPLAY(F) --PRESS 5\n");
printf("\nDISPLAY(R) --PRESS 6\n");
printf("\nEXIT --PRESS 7\n");
printf("\n\nENTER YOUR CHOICE::\n");
scanf("%d",&n);
switch(n)
{
case 1:
while(1)
{
flag=0;
clrscr();
printf("INSERT A NODE ::\n");
printf("\t\tAT FIRST -PRESS 1.\n");
printf("\t\tAFTER A NODE -PRESS 2.\n");
printf("\t\tBEFORE A NODE -PRESS 3.\n");
printf("\t\tAT LAST -PRESS 4.\n");
printf("\t\tEXIT FROM HERE-PRESS 5.\n");
printf("\n\nENTER YOUR CHOICE::\n");
scanf("%d",&n);
switch(n)
{
case 1:
printf("\nENTER A ELEMENT FOR INSERTION\n");
scanf("%d",&num);
finsert(num);
printf("\n%d IS INSERT AT FIRST PROPERLY\n",num);
break;
case 2:
printf("\nENTER A ELEMENT FOR INSERTION\n");
scanf("%d",&num);
printf("AFTER WHICH ELEMENT YOU WANT TO INSERT\n");
scanf("%d",&num1);
ainsert(num,num1);
break;
case 3:
printf("ENTER A ELEMENT FOR INSERTION\n");
scanf("%d",&num);
printf("BEFORE WHICH ELEMENT YOU WANT TO INSERT\n");
scanf("%d",&num1);
binsert(num,num1);
break;
case 4:
printf("ENTER AN ELEMENT FOR INSERT IN LAST\n");
scanf("%d",&num);
linsert(num);
break;
case 5:
printf("\nTHANK YOU FOR USING INSERT OPERETION\n");
flag=1;
break;
}
getch();
if(flag==1)
break;
}
break;
case 2:
while(1)
{
flag=0;
clrscr();
printf("DELETE A NODE ::\n");
printf("\t\tAT FIRST -PRESS 1.\n");
printf("\t\tAFTER A NODE -PRESS 2.\n");
printf("\t\tBEFORE A NODE -PRESS 3.\n");
printf("\t\tAT LAST -PRESS 4.\n");
printf("\t\tEXACT A NODE -PRESS 5.\n");
printf("\t\tEXIT FROM HERE-PRESS 6.\n");
printf("\n\nENTER YOUR CHOICE::\n");
scanf("%d",&n);
switch(n)
{
case 1:
fdelete();
break;
case 2:
printf("\nENTER AFTER WHICH ELEMENT YOU WANT TO DELETE A NODE\n");
scanf("%d",&num);
adelete(num);
break;
case 3:
printf("\nENTER BEFORE WHICH ELEMENT YOU WANT TO DELETE A NODE\n");
scanf("%d",&num);
bdelete(num);
break;
case 4:
ldelete();
break;
case 5:
printf("WHICH ELEMENT CONTAIN NODE YOU WANT TO DELETE:\n");
scanf("%d",&num);
edelete(num);
break;
case 6:
printf("THANK YOU FOR USING DELETE OPERETION");
flag=1;
break;
}
getch();
if(flag==1)
break;
}
break;
case 3:
printf("WHICH ELEMENT YOU WANT TO SEARCH ?");
scanf("%d",&num);
search(num);
break;
case 4:
num=count();
printf("AT PRESENT LINKLIST CONTAIN %d NODES\n",num);
break;
case 5:
fdisplay();
break;
case 6:
rdisplay();
break;
case 7:
printf("\n\nTHANK YOU FOR USING THIS PROGRAM\n");
getch();
exit(0);
}
getch();
}
}
