https://www.interviewbit.com/problems/detect-and-remove-loop-from-a-linked-list/



/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
 typedef ListNode node;
ListNode* Solution::solve(ListNode* a) {
    node*b,*c,*x;
    b=c=x=a;
    /*while(x->next!=NULL and x!=NULL)
    {
        x=x->next->next;
    }*/
    cout<<"1111111111"<<endl;
    while(b!=c)
    {
        b=b->next;c=c->next->next;
        if(b==NULL || c==NULL)return a;
    }

    c=c->next;
    cout<<"2222222222222"<<endl;
    int count=1;
    while(c!=b)
    {
        c=c->next;
        count++;
        cout<<count;
    }
    cout<<"333333333333333"<<endl;
    node*d,*e;
    d=e=a;
    for(int i=0;i<count;i++)
    {
        e=e->next;
    }
    cout<<"44444444444"<<endl;
    while(d!=e)
    {
        d=d->next;e=e->next;
    }
    cout<<"55555555555555"<<endl;
    cout<<d->val<<endl;

    for(int i=1;i<count;i++)
    {
        e=e->next;
    }
    cout<<"666666666666666"<<endl;
    e->next=NULL;
    return a;
}