Cycle Detection

Floyd'sTortoise&Hare.cpp

int detectLoop(Node * list) {
    if (!list) 
        return 0;

    Node * tortoise = list;
    Node * hare = list;

    do {
        if (!(hare = hare->next) || !(hare = hare->next))
            return 0;
        tortoise = tortoise->next;
    } while (tortoise != hare);

    return 1;
}