C语言——约瑟夫环

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/Eleanor_12/article/details/53821928

设编号1,2…..n的n个人围坐在一圈，任选一个正整数作为报数的上限值，从第k个人开始按顺时针报数，数到m的那个人出局，他的顺时针方向下一位又从1开始报数，数到m的那个人又出局，以此类推，直到所有人出局为止，请用链表写一个函数找出每轮的幸存者。（假设n个人已经插入链表）

struct{

int num;

struct node *next;

}

typedef struct node Node;

typedef Node* LINK;

void handle(int m,int k,Link *head)；

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct node
{
    int num;
    struct node *next;
};

typedef struct node Node;
typedef Node* Link;

void create_link(Link *head)
{
    *head = (Link)malloc(sizeof(Node));
    if(*head == NULL)
    {
        printf("malloc error!\n");
	exit(1);
    }
    (*head)->next = *head;
    (*head)->num = 0;
}

void insert_link(Link *head,Link *newnode)
{
    Link temp = (*head)->next;

    while(temp->next != *head)
    {
        temp = temp->next;
    }

    (*newnode)->next = temp->next;
    temp->next = *newnode;

    ((*head)->num)++;
}

void delete(Link *head,int i)
{
    if((*head)->next == *head)
    {
        return ;
    }
    Link ptr = *head;
    Link temp = (*head)->next;

    while(temp != *head)
    {
        if(temp->num == i)
	{
	    ptr->next = temp->next;
	    free(temp);
	    temp = NULL;
	    ((*head)->num)--;
	    return ;
	}
	ptr = temp;
        temp = temp->next;
    }
}

void print(Link head)
{
    Link temp = head->next;
    while(temp != head)
    {
        printf("%d\n",temp->num);
        temp = temp->next;
    }
    return ;
}

void handle(int m,int k,Link *head)
{
    int flag = 1;
    
    if((*head)->next == *head || (*head)->next->next == *head)
    {
        printf("already done!\n");
        return ;
    }

    Link temp = *head;
    for(; k > 0; k--)
    {
        temp = temp->next;
	if(temp == *head)
	{
	    temp = temp->next;
	}
    }

    while((*head)->num > 1)
    {
        if(temp == *head)
	{
	    temp = temp->next;
	}
	if(flag == m)
	{
	    Link dtmp = temp;
	    printf("delete num:%d\n",dtmp->num);
	    delete(head,dtmp->num);
	    flag = 1;
	    temp = temp->next;
	    continue;
	}
	flag++;
	temp = temp->next;
    }

    return ;

}

int main()
{
    int n;
    int k;
    int m;
    int i;
    Link head;
    Link newnode;
    
    printf("Please input n:\n");
    scanf("%d",&n);
    printf("Please input m:\n");
    scanf("%d",&m);
    printf("Please input k:\n");
    scanf("%d",&k);

    create_link(&head);

    for(i = 1; i <= n; i++)
    {
        newnode = (Link)malloc(sizeof(Node));
	if(newnode == NULL)
	{
	    printf("malloc error!\n");
	    exit(1);
	}
	newnode->num = i;
	insert_link(&head,&newnode);
    }
    handle(m,k,&head);
    print(head);

    return 0;
}