2-6.环形单链表的约瑟夫环问题.cpp

typedef struct Node {
    int value;
    Node* next;

    Node( int data ) {
        this.value = data;
    }
} Node;

Node* josephusKill( Node* head, int m ) {
    if( head == NULL || head->next == head || m < 1 ) return head;

    Node* last = head;
    while( last->next != head ) {
        last = last->next;
    }
    int count = 0;
    while( head != last ) {
        if( ++count == m ) {
            last->next = head->next;
            count = 0;
        }
        else {
            last = last->next;
        }
        head = last->next;
    }

    return head;
}