sms2.cpp

描述学生管理系统的程序代码

        printf("**************************************FOUND************************************\n");
        printf("-------------------------------------------------------------------------------\n");
        printf("|     Num    |    Name    |  sc1  |  sc2  |  sc3  |  Sum  |   Ave   | Order |\n");
        printf("-------------------------------------------------------------------------------\n");
        printf("|     %4s   |    %4s    |  %3d  |  %3d  |  %3d  |  %3d  |  %4.2f  |  %-5d|\n",
            p1->num,p1->name,p1->score[0],p1->score[1],p1->score[2],p1->sum,p1->average,p1->order);
        printf("-------------------------------------------------------------------------------\n");
        printf("***************************************END**************************************\n");
        printf("Are you sure to modify the student Y/N ?"); /*提示是否要删除,输入Y删除,N则退出*/
        for(;;)
        {
            scanf("%c",&c);
            if(c=='n'||c=='N') break;  /*如果不删除,则跳出本循环*/
            if(c=='y'||c=='Y')
            {
                if(p1==head)       /*若p1==head，说明被删结点是首结点*/
                    head=p1->next;     /*把第二个结点地址赋予head*/
                else
                    p2->next=p1->next;  /*否则将一下结点地址赋给前一结点地址*/
                n=n-1;
               // printf("\nNum %s student have been delete1d.\n",s);
               // printf("Don't forget to save.\n");
                sort(head);
                break;  /*删除后就跳出循环*/
            }
        }
    }
    else
        printf("\nThere is no num %s student on the list.\n",s);  /*找不到该结点*/
    //return(head);
    STUDENT *p3,*p4,*p5, *new1;
    int m,sum1,i;
    p4=head;  /*使p4指向第一个结点*/
    new1= (STUDENT *)malloc(LEN);
    p3=new1;   /*p3指向要插入的结点*/
    printf("\nPlease enter a modified record.\n");      /*提示输入记录信息*/
    printf("Enter the num:");
    scanf("%s",new1->num);
    printf("Enter the name:");
    scanf("%s",new1->name);
    printf("Please enter the %d scores.\n",3);
    sum1=0;    /*保存新记录的总分，初值为0*/
    for(i=0;i<3;i++)
    {
        do{
            printf("score%d:",i+1);
            scanf("%d",&new1->score[i]);
            if(new1->score[i]>100||new1->score[i]<0)
            printf("Data error,please enter again.\n");
        }while(new1->score[i] >100||new1->score[i] <0);
        sum1=sum1+new1->score[i];    /*累加各门成绩*/
    }
    new1->sum=sum1;    /*将总分存入新记录中*/
    new1->average=(float)sum1/3;
    new1->order=0;
    if(head==NULL)  /*原来的链表是空表*/
    {
        head=p3;
        p3->next=NULL;
    }  /*使p3指向的结点作为头结点*/
    else
    {
        while((p4!=NULL) && (p3->average<p4->average))
        {
            p5=p4;   /*使p5指向刚才p4指向的结点*/
            p4=p4->next;   /*p4后移一个结点*/
        }
        if(p4 != NULL && p3->average>=p4->average)
        {
            if(head==p4)head=p3;   /*插到原来第一个结点之前*/
            else
                p5->next=p3;      /*插到p5指向的结点之后*/
            p3->next=p4;
        }
        else
        {
            p5->next=p3;p3->next=NULL;
        } /*插到最后的结点之后*/
    }
    m=m+1; /*结点数加1*/
    head=sort(head);  /*调用排序的函数,将学生成绩重新排序*/
    printf("\nStudent  %s have been modifid.\n",new1->name);
    printf("Don't forget to save the new1 file.\n");
    return head;



}


/*排序函数*/
STUDENT *sort(STUDENT *head)
{
    if( head == NULL)
    {
        printf("the list is empty, please insert data before!!!\n");
        return NULL;
    }
    int i=0;                       /*保存名次*/
    STUDENT *p1,*p2,*t,*temp;      /*定义临时指针*/
    temp=head->next;               /*将原表的头指针所指的下一个结点作头指针*/
    head->next=NULL;               /*第一个结点为新表的头结点*/
    while(temp!=NULL)              /*当原表不为空时，进行排序*/
    {
        t=temp;             /*取原表的头结点*/
        temp=temp->next;    /*原表头结点指针后移*/
        p1=head;             /*设定移动指针p1，从头指针开始*/
        p2=head;             /*设定移动指针p2做为p1的前驱，初值为头指针*/
        while(p1!=NULL && t->average<p1->average)  /*作成绩平均分比较*/
        {
            p2=p1;            /*待排序点值小，则新表指针后移*/
            p1=p1->next;
        }
        if(p1==p2)      /*p1==p2，说明待排序点值大，应排在首位*/
        {
            t->next=p1;     /*待排序点的后继为p*/
            head=t;         /*新头结点为待排序点*/
        }
        else    /*待排序点应插入在中间某个位置p2和p1之间，如p为空则是尾部*/
        {
            t->next=p1;   /*t的后继是p1*/
            p2->next=t;   /*p2的后继是t*/
        }
    }
    p1=head;         /*已排好序的头指针赋给p1，准备填写名次*/
    while(p1!=NULL)  /*当p1不为空时，进行下列操作*/
    {
        i++;           /*结点序号*/
        p1->order=i;   /*将结点序号赋值给名次*/
        p1=p1->next;   /*指针后移*/
    }
    printf("Sorting is sucessful.\n");   /*排序成功*/
    return (head);
}

/*插入记录函数*/
STUDENT  *insert(STUDENT *head)
{
    STUDENT *p0,*p1,*p2, *new1;
    int n,sum1,i;
    p1=head;  /*使p1指向第一个结点*/
    new1= (STUDENT *)malloc(LEN);
    p0=new1;   /*p0指向要插入的结点*/
    printf("\nPlease enter a new1 record.\n");      /*提示输入记录信息*/
    printf("Enter the num:");
    scanf("%s",new1->num);
    printf("Enter the name:");
    scanf("%s",new1->name);
    printf("Please enter the %d scores.\n",3);
    sum1=0;    /*保存新记录的总分，初值为0*/
    for(i=0;i<3;i++)
    {
        do{
            printf("score%d:",i+1);
            scanf("%d",&new1->score[i]);
            if(new1->score[i]>100||new1->score[i]<0)
            printf("Data error,please enter again.\n");
        }while(new1->score[i] >100||new1->score[i] <0);
        sum1=sum1+new1->score[i];    /*累加各门成绩*/
    }
    new1->sum=sum1;    /*将总分存入新记录中*/
    new1->average=(float)sum1/3;
    new1->order=0;
    if(head==NULL)  /*原来的链表是空表*/
    {
        head=p0;
        p0->next=NULL;
    }  /*使p0指向的结点作为头结点*/
    else
    {
        while((p1!=NULL) && (p0->average<p1->average))
        {
            p2=p1;   /*使p2指向刚才p1指向的结点*/
            p1=p1->next;   /*p1后移一个结点*/
        }
        if(p1 != NULL && p0->average>=p1->average)
        {
            if(head==p1)head=p0;   /*插到原来第一个结点之前*/
            else
                p2->next=p0;      /*插到p2指向的结点之后*/
            p0->next=p1;
        }
        else
        {
            p2->next=p0;p0->next=NULL;
        } /*插到最后的结点之后*/
    }
    n=n+1; /*结点数加1*/
    head=sort(head);  /*调用排序的函数,将学生成绩重新排序*/
    printf("\nStudent  %s have been inserted.\n",new1->name);
    printf("Don't forget to save the new1 file.\n");
    return head;
}

/*保存数据到文件函数*/
void save(STUDENT *head)
{
    if( head == NULL)
    {
        printf("the list is empty, please insert data before!!!\n");
        return;
    }
    FILE *fp;        /*定义指向文件的指针*/
    STUDENT *p;      /* 定义移动指针*/
    char outfile[10];
    printf("Enter outfile name,for example c:\\score\n");
    scanf("%s",outfile);
    if((fp=fopen(outfile,"wb"))==NULL)   /*为输出打开一个二进制文件,为只写方式*/
    {
        printf("Cannot open the file\n");
        return;    /*若打不开则返回菜单*/
    }
    printf("\nSaving the file......\n");
    p=head;                    /*移动指针从头指针开始*/
    while(p!=NULL)        /*如p不为空*/
    {
        fwrite(p,LEN,1,fp);     /*写入一条记录*/
        p=p->next;        /*指针后移*/
    }
    fclose(fp);      /*关闭文件*/
    printf("Save the file successfully!\n");
}

/* 从文件读数据函数*/
STUDENT *load()
{
    STUDENT *p1,*p2,*head=NULL;    /*定义记录指针变量*/
    FILE *fp;            /* 定义指向文件的指针*/
    char infile[10];
    printf("Enter infile name,for example c:\\score\n");
    scanf("%s",infile);
    if((fp=fopen(infile,"rb"))==NULL)   /*打开一个二进制文件，为只读方式*/
    {
        printf("Can not open the file.\n");
        return(head);
    }
    printf("\nLoading the file!\n");
    p1=(STUDENT *)malloc(LEN);   /*开辟一个新单元*/
    if(!p1)
    {
        printf("Out of memory!\n");
        return(head);
    }
    head=p1;         /*申请到空间，将其作为头指针*/
    while(!feof(fp))  /*循环读数据直到文件尾结束*/
    {
        if(fread(p1,LEN,1,fp)!=1) break;  /*如果没读到数据，跳出循环*/
        p1->next=(STUDENT *)malloc(LEN);  /*为下一个结点开辟空间*/
        if(!p1->next)
        {
            printf("Out of memory!\n");
            return (head);
        }
        p2=p1;         /*使p2指向刚才p1指向的结点*/
        p1=p1->next;   /*指针后移，新读入数据链到当前表尾*/
    }
    p2->next=NULL;   /*最后一个结点的后继指针为空*/
    fclose(fp);
    printf("You have success to read data from the file!\n");
    return (head);
}

//释放原链表的内存
void memoryFree(STUDENT * head)
{
    if(head == NULL)
       return;
    STUDENT *p = head, *parent;
    while(p != NULL)
    {
        parent = p;
        p = p->next;
        free(parent);
    }
    if(head != NULL)
       printf("error!!!\n");
}