2021-08-12：约瑟夫环问题。给定一个链表头节点head，和一个正数m，从头开始，每次数到m就杀死当前节点 ，然后被杀节点

package main

import "fmt"

func main() {
    head := NewNode(1)
    head.next = NewNode(2)
    head.next.next = NewNode(3)
    head.next.next.next = NewNode(4)
    head.next.next.next.next = NewNode(5)
    head.next.next.next.next.next = head
    ret := josephusKill2(head, 3)
    fmt.Println(ret.value)
}

type Node struct {
    value int
    next  *Node
}

func NewNode(data int) *Node {
    ans := &Node{}
    ans.value = data
    return ans
}

func josephusKill2(head *Node, m int) *Node {
    if head == nil || head.next == head || m < 1 {
        return head
    }
    cur := head.next
    size := 1 // tmp -> list size
    for cur != head {
        size++
        cur = cur.next
    }
    live := getLive(size, m) // tmp -> service node position
    live--
    for live != 0 {
        head = head.next
        live--
    }
    head.next = head
    return head
}

func getLive(n int, m int) int {
    if n == 1 {
        return 1
    }
    return (getLive(n-1, m)+m-1)%n + 1
}