Python3下约瑟夫环的不同实现方式

基于python的约瑟夫环

思路一：递归

# 约瑟夫环：递归
def KillYuesefu(n,m):
    if(n == 1):
        return 0
    return (KillYuesefu(n - 1, m) + m ) % n 
    
def main():
    for num in range(1,11):
        lastindex=KillYuesefu(num,8)+1
        print(lastindex)

if __name__ == "__main__":
    main()

　　

思路二：单向链表

# 约瑟夫环：单向循环链表

class Node:
    def __init__(self,Id,NextNode):
        self.Id=Id
        self.NextNode=NextNode



def GenerateNodeLinkList(listLen):
    header = Node(1,None)
    tmpPreNode = header
    if(listLen < 1 ):
        return None
    elif listLen>1:
        for i in range(2,listLen):
            tmpNode = Node(i,None)
            tmpPreNode.NextNode=tmpNode
            tmpPreNode=tmpNode
    return header

def GenerateNodeLinkList_Yuesefu(n):
    # 初始化链表
    header = Node(1,None)
    tmpPreNode = header
    if(n < 1 ):
        return None
    elif n > 1:
        for i in range(2 , n+1):
            tmpNode = Node(i,None)
            tmpPreNode.NextNode=tmpNode
            tmpPreNode=tmpNode
    tmpPreNode.NextNode=header

    return header


def KillYuesefu(nodelist,m):
    curIndex=1
    curNode=nodelist
    preNode=None
    
    while(curNode!=preNode):
        if curIndex==m:
            # 杀死当前节点
            print("%d" % (curNode.Id),end=" --> ")
            curNode=curNode.NextNode
            preNode.NextNode=curNode
            curIndex=1
        else:
            curIndex=curIndex+1
            preNode=curNode
            if curNode.NextNode is not None:
                curNode=curNode.NextNode
            else:
                break
    print("alive %d" % curNode.Id,end=" ")
    print("OVER")


def main(): 
    for num in range(1,11):
        print("begin num is %d" % num)
        nodelist=GenerateNodeLinkList_Yuesefu(num)
        KillYuesefu(nodelist,8)


if __name__ == "__main__":
    main()

　　

思路三：双向链表

# 约瑟夫环：双向循环链表

class Node:
    def __init__(self,Id,Name,PreNode,NextNode):
        self.Id=Id
        self.Name=Name
        self.PreNode=PreNode
        self.NextNode=NextNode



def GenerateNodeLinkList(listLen):
    header = Node(1,"Name1",None,None)
    tmpPreNode = header
    if(listLen < 1 ):
        return None
    elif listLen>1:
        for i in range(2,listLen):
            tmpNode = Node(i,"Name-%d" % i,tmpPreNode,None)
            tmpPreNode.NextNode=tmpNode
            tmpPreNode=tmpNode
    return header

def GenerateNodeLinkList_Yuesefu(n):
    # 初始化链表
    header = Node(1,"Name1",None,None)
    tmpPreNode = header
    if(n < 1 ):
        return None
    elif n > 1:
        for i in range(2 , n):
            tmpNode = Node(i,"Name-%d" % i,tmpPreNode,None)
            tmpPreNode.NextNode=tmpNode
            tmpPreNode=tmpNode
    tmpPreNode.NextNode=header
    header.PreNode=tmpPreNode

    return header


def KillYuesefu(nodelist,m):
    curIndex=1
    curNode=nodelist
    
    while(curNode is not None):
        if curIndex==m:
            # 杀死当前节点
            print("Id=%d,Name=%s" % (curNode.Id,curNode.Name),end=" --> ")
            tmp = curNode.PreNode
            if tmp is None:
                # 前面没有节点了，结束
                break
            curNode=curNode.NextNode
            if tmp==curNode:
                # 重叠，结束
                break
            tmp.NextNode=curNode
            curNode.PreNode=tmp
            curIndex=1
        else:
            curIndex=curIndex+1
            curNode=curNode.NextNode
    print("OVER")

def main():
    nodelist=GenerateNodeLinkList_Yuesefu(10)
    KillYuesefu(nodelist,6)

if __name__ == "__main__":
    main()