C 单链表 实现约瑟夫环

list.h

#ifndef _List_H
#define _List_H
typedef int ElementType;

struct Node;
typedef struct Node *PtrToNode;
typedef PtrToNode List;
typedef PtrToNode Position;

//定义一个空链表
List MakeEmpty();

//判断链表是否为空，0为空，1为非空
int IsEmpty( List L );

//int IsLast( Position P, List L );

//查找数据X在链表L中的位置，若不存在返回NULL
Position Find( ElementType X,List L );

//从链表中删除数据为X的结点
void Delete( ElementType X,List L);

// 从链表中删除P结点
void Delete_two( Position P );

//查找数据X在链表L中的直接前驱结点
Position FindPrevious( ElementType X, List L );

void Insert( ElementType X, Position P );
void DeleteList( List L );
//Position Header( List L);
//Position First( List L );
//Position Advice( Position P);
//ElementType Retrieve( Position P);

#endif     /*_List_H*/

/*Place in the Implementation file */
struct Node
{
    ElementType Element;
    Position Next;
};

list.c

#include "list.h"
#include <stdlib.h>

/*make a empty list,Head pointer to it's head*/
List MakeEmpty()
{
    PtrToNode L;
    L=(struct Node*)malloc(sizeof(struct Node));
    L->Next = L;
    return L;
}

/*Return true if L is empty*/
int IsEmpty( List L )
{
    if( L->Next == L )
        return 1;
    else
        return 0;
}

/*Return true if P is the last position in list L*/
/*int IsLast( Position P, List L )
{
    return P->Next==NULL;
}*/

/*Return Position of X in L;NULL if not found*/
Position Find( ElementType X,List L )
{
    Position P;
    P=L->Next;
    while(P != L && P->Element != X)
        P=P->Next;
    if( P == L )
        return NULL;
    else
        return P;
}

/*Delete first occurrence of X from a list*/
/*Assume use of a header node*/
void Delete( ElementType X, List L )
{
    Position P, TmpCell;

    P = FindPrevious( X, L );
    if( P != NULL )
    {
        TmpCell = P->Next;
        P->Next = TmpCell->Next;
        free( TmpCell );
    }
}

/* If X is not found, then Next field of returned */
/* Position id NULL*/
/*Assumes a header */
Position FindPrevious( ElementType X, List L )
{
    Position P;

    P = L;
    while( P->Next != L && P->Next->Element != X )
        P = P->Next;
    if( P->Next == L )
        return NULL;
    else
        return P;
}

void Delete_two( Position P)
{
    Position preP, TmpCell;

    preP = FindPrevious( P->Element , P );
    if( preP != NULL )
    {
        TmpCell = preP->Next;
        preP->Next = TmpCell->Next;
        free( TmpCell );
    }
}

/* Insert (after legal position P) */
/* Header implementtation assumed */
/* Parameter L is unused in this implementation */
void Insert( ElementType X, Position P )
{
    Position TmpCell;

    TmpCell = ( Position )malloc( sizeof ( struct Node ) );
    if( TmpCell == NULL)
    {
       //printf( "Out of space!!!" );
    }
    TmpCell->Element = X;
    TmpCell->Next = P->Next;
    P->Next = TmpCell;
}
/* Correct DeleteList algorithm*/
void DeleteList( List L )
{
    Position P, Tmp;

    P = L->Next;
    L->Next = NULL;
    while( P != NULL)
    {
        Tmp = P->Next;
        free(P);
        P=Tmp;
    }
}

Joseph.c

#include <stdio.h>
#include "list.h"

void main()
{
    //定义链表L
    List L;
    L=MakeEmpty();
    Position P;
    //输入人数n和m
    int n ,m = 4 , tamp;
    //获取人数n
    printf("请输入人的个数n:\n");
    scanf("%d",&n);
    if( n == 0 )
    {
        printf("请输入人数n\n");
        return;
    }
    else
    {
        int i;
        for( i = 0 ; i<n ; i++ )
        {
            if(i == 0 )
            {
                Insert( i+1 , L );
                P = L->Next;
            }
            else
            {
                Insert( i+1 , P );
                P = P->Next;
            }
        }
    }
    //获取m
    printf("请输入m:\n");
    scanf("%d",&m);
    tamp = 1;
    P = L->Next;
    while( !IsEmpty( L ) )
    {
        if( tamp == m )
        {
            printf("%d",P->Element);
            tamp = 0;
            Delete( P->Element , L );
        }
        else
        {
            tamp++;
            P = P->Next;
            if( P == L )
                P = P->Next;
        }

    }
    printf("\n");
}

Github:https://github.com/Wave-Maker/DataStructs