Finding Node at Intersection

[CoderfromIN]

Hey, Can someone explain? There's a error in this code to find the node at which the intersection of two singly linked lists begins. Where is it going wrong? Ref - InterviewBit (https://www.interviewbit.com/c-interview-questions/)


// Function to get the intersection point
// of the given linked lists
int getIntersectionNode(Node* head1, Node* head2)
{
Node *curr1 = head1, *curr2 = head2;

// While both the pointers are not equal
while (curr1 != curr2) {

// If the first pointer is null then
// set it to point to the head of
// the second linked list
if (curr1 == NULL) {
curr1 = head2;
}

// Else point it to the next node
else {
curr1 = curr1->next;
}

// If the second pointer is null then
// set it to point to the head of
// the first linked list
if (curr2 == NULL) {
curr2 = head1;
}

// Else point it to the next node
else {
curr2 = curr2->next;
}
}

// Return the intersection node
return curr1->data;
}