倒叙输出

      将一个链表倒序。

 

#include <stdio.h>
#include <malloc.h>


typedef struct _STUDENT_INFO_
{
    int num;
    struct _STUDENT_INFO_ *next;
}STUDENT_INFO;


STUDENT_INFO *Creat_List(void)
{
    STUDENT_INFO *head=NULL;
    STUDENT_INFO *pcurrent=NULL,*ptemp=NULL;
    int stu_num=0,n=0;

    do
    {
        printf("please input the number of student:");
        scanf("%d",&stu_num);
        if( stu_num == 0 )
            printf("sorry,the number is error!\n");
        else
            printf("\n");

    }while( stu_num == 0 );

    while( n<stu_num )
    {
        n=n+1;

        pcurrent=(STUDENT_INFO *)malloc(sizeof(STUDENT_INFO));
        if( pcurrent == NULL )
        {
            printf("malloc error!\n");
            break;
        }
        else
           pcurrent->num=stu_num-n+1;

        if( n == 1 )
            head=pcurrent;
        else
            ptemp->next=pcurrent;

        ptemp=pcurrent;
    }

    ptemp->next=NULL;
    return(head);
}

STUDENT_INFO *Reverse_Output(STUDENT_INFO *head)
{
    STUDENT_INFO *pcurrent=NULL,*ptemp=NULL,*pnext=NULL;

    if(head == NULL)
    {
        printf("no infomation to been printed,please check it!\n");
        return(NULL);
    }

    for( pcurrent=head;pcurrent; )
    {
        pnext=pcurrent->next;

        if( pcurrent==head )
            pcurrent->next=NULL;
        else if( pcurrent->next==NULL )
        {
            pcurrent->next=ptemp;
            head=pcurrent;
            break;
        }
        else
            pcurrent->next=ptemp;

        ptemp=pcurrent;
        pcurrent=pnext;
    }

    return(head);
}

void Print_Infor(STUDENT_INFO *head)
{
    STUDENT_INFO *ptemp;

    if(head==NULL)
    {
        printf("Information error,please check it!\n");
        return;
    }

    ptemp=head;
    while(ptemp)
    {
        printf("Number: %d\n",ptemp->num);
        ptemp=ptemp->next;
    }

    return;
}

int main(int argc,char *argv[])
{
    STUDENT_INFO *head=NULL;

    head=Creat_List();
    Print_Infor(head);
    printf("\n");
    head=Reverse_Output(head);
    Print_Infor(head);

    return 0;
}