题解 | #环形链表的约瑟夫问题#

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param n int整型 
 * @param m int整型 
 * @return int整型
 */
 #include<stdlib.h>
typedef struct LSnode
{
    int data;
    struct LSnode* next;
}LSnode;
LSnode* LSnode_space(int n)
{
    LSnode* p1 = (LSnode*) malloc(sizeof(LSnode));
    p1->data = n;
    p1->next = NULL;
    return p1;
}
LSnode* LSnode_creat(int n)
{
    //创建扫兵卫
    LSnode* phead = LSnode_space(-1);
    LSnode* tmp = phead;//储存链头
    int i = 1;
    while(i <= n)
    {
        LSnode* newnode = LSnode_space(i);
        phead->next = newnode;
        phead = newnode;
        i++;
    }
    LSnode* ed = phead->next = tmp->next;//首位相连
    free(tmp);
    phead = tmp = NULL;
    return ed;
}
int ysf(int n, int m ) {
    // write code here
    //创建闭环
    LSnode* phead = LSnode_creat(n);
    //计算
    while(phead != phead->next)//只有一个
    {
        int count = 1;
        LSnode* prev = NULL;//储存上一个节点
        while(count < m)
        {
            prev = phead;
            phead = phead->next;
            count++;
        }
        //删除
        LSnode* del = phead;
        prev->next = phead->next;
        phead = phead->next;//从下一个开始
        free(del);
        del = NULL;
    }
    return phead->data;
}
//yeyeyeyeye