how to check whether a linked list is circular.

Answers were Sorted based on User's Feedback



how to check whether a linked list is circular...

Answer / coder_1

Create two pointers, each set to the start of the list.
Update each as follows:

while (pointer1) {
pointer1 = pointer1->next;
pointer2 = pointer2->next; if (pointer2)
pointer2=pointer2->next;
if (pointer1 == pointer2) {
print (\"circular\n\");
}
}

If a list is circular, at some point pointer2 will wrap
around and be either at the item just before pointer1, or
the item before that. Either way, it?s either 1 or 2 jumps
until they meet.

Is This Answer Correct ?    86 Yes 34 No

how to check whether a linked list is circular...

Answer / pratyu

node *ptr1,*ptr2;
ptr1=head;
ptr2=head->next;
while(ptr2)
{
if(ptr1==ptr2)
printf("circular linked list");

ptr2=ptr2->next;
}
printf("not a circular linked list");

Is This Answer Correct ?    31 Yes 7 No

how to check whether a linked list is circular...

Answer / priya

This is the function to check if the linklist is circular:

bool CLinklist::ifcircular()
{
node *ptr1,*ptr2;
ptr1 = front;
ptr2 = front;

while(ptr1)
{
ptr1 = ptr1->link;
ptr2 = ptr2->link;

if(ptr2)
ptr2 = ptr2->link;

if(ptr1 == ptr2)
return 1;
}
}

Is This Answer Correct ?    15 Yes 7 No

how to check whether a linked list is circular...

Answer / shruti

consider home pointer as the starting pointer of the linked
list.
consider temp as the temporary pointer.


temp = home;
while(temp != NULL)
{
if(temp -> next == start)
{
flag = 1;
break;
}
else
flag = 0;
temp = temp -> next;
}

if(flag == 1)
printf("Circular");
else
printf("Not circular");

Is This Answer Correct ?    30 Yes 30 No

how to check whether a linked list is circular...

Answer / nirwal

hi All

specialy the two pointer solution techies


what about the loop in the link list ?

how you differentiate b/w circular list and list having the
loop?

Think again...........

Is This Answer Correct ?    4 Yes 4 No

how to check whether a linked list is circular...

Answer / abhi

while(q->next->next=NULL)
{
p=p->next;
q=q->next->next;
if(p==q)
{
printf("loof is find");
break;
}
}

Is This Answer Correct ?    2 Yes 2 No

how to check whether a linked list is circular...

Answer / shahid khan abbasi

bool hasCircle(List l)
{
Iterator i = l.begin(), j = l.begin();
while (true) {
// increment the iterators, if either is at the end,
you're done, no circle
if (i.hasNext()) i = i.next(); else return false;

// second iterator is travelling twice as fast as first
if (j.hasNext()) j = j.next(); else return false;
if (j.hasNext()) j = j.next(); else return false;

// this should be whatever test shows that the two
// iterators are pointing at the same place
if (i.getObject() == j.getObject()) {
return true;
}
}
}

Is This Answer Correct ?    2 Yes 3 No

how to check whether a linked list is circular...

Answer / burmeselady

start from pointer1
check all node's next pointer is null or not starting from
pointer1 until pointer1
if a node next pointer is null=> it is not circular.
else it is circular

Is This Answer Correct ?    5 Yes 7 No

how to check whether a linked list is circular...

Answer / ishan

by checking whether link field in the last node contains
the address of the first node.

Is This Answer Correct ?    17 Yes 20 No

how to check whether a linked list is circular...

Answer / lohitha

node *ptr1,*ptr2;
ptr1=head;
ptr2=head->next;
while(ptr2)
{
if(ptr1==ptr2)
{
printf("circular linked list");
break;
}
ptr2=ptr2->next;
}
printf("not a circular linked list");

Is This Answer Correct ?    3 Yes 6 No

Post New Answer

More C Code Interview Questions

write a c-program to display the time using FOR loop

3 Answers   HCL,


Give a oneline C expression to test whether a number is a power of 2?

25 Answers   EA Electronic Arts, Google, Motorola,


Write a C program to add two numbers before the main function is called.

11 Answers   Infotech, TC,


#include<stdio.h> main() { int a[2][2][2] = { {10,2,3,4}, {5,6,7,8} }; int *p,*q; p=&a[2][2][2]; *q=***a; printf("%d----%d",*p,*q); }

1 Answers  


void main() { char ch; for(ch=0;ch<=127;ch++) printf(“%c %d \n“, ch, ch); }

1 Answers  


void main() { int *i = 0x400; // i points to the address 400 *i = 0; // set the value of memory location pointed by i; }

2 Answers  


void main() { printf(“sizeof (void *) = %d \n“, sizeof( void *)); printf(“sizeof (int *) = %d \n”, sizeof(int *)); printf(“sizeof (double *) = %d \n”, sizeof(double *)); printf(“sizeof(struct unknown *) = %d \n”, sizeof(struct unknown *)); }

1 Answers  


/*what is the output for*/ void main() { int r; printf("Naveen"); r=printf(); getch(); }

4 Answers  


There were 10 records stored in “somefile.dat” but the following program printed 11 names. What went wrong? void main() { struct student { char name[30], rollno[6]; }stud; FILE *fp = fopen(“somefile.dat”,”r”); while(!feof(fp)) { fread(&stud, sizeof(stud), 1 , fp); puts(stud.name); } }

1 Answers  


Write a program to model an exploding firecracker in the xy plane using a particle system

1 Answers   HCL,


what is brs test reply me email me kashifabbas514@gmail.com

0 Answers  


void pascal f(int i,int j,int k) { printf(“%d %d %d”,i, j, k); } void cdecl f(int i,int j,int k) { printf(“%d %d %d”,i, j, k); } main() { int i=10; f(i++,i++,i++); printf(" %d\n",i); i=10; f(i++,i++,i++); printf(" %d",i); }

1 Answers  


Categories