Cycle detection- getting wrong answer

getting wrong answer in some of the test case

you have only checked whether cycle is present or not

but you also have to remove cycle in the same function

sir, the head is passed by value not by refrence so,if i make changr int he linked list it will not really change the linked list

yes you have to pass it by reference
like this
bool floydCycleRemoval(Node *&head)