请问这是什么意思？

--------------------Configuration: 292页4题2 - Win32 Debug--------------------
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/292页4题2.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

292页4题2.exe - 1 error(s), 0 warning(s)

又不贴代码

.....

    - -
              代码有很多，我还是第一次打出这么多的代码。。。

                    好累啊


#include"stdio.h"
#include"stdlib.h"
typedef struct
{
    char id[8];
    char name[10];
    char sex[2];
    float score[3];
}student;
void cptcourseavg(student *ps,int n)
{
    int i,j;
    float sum;
    for(i=0;i<3;i++)
    {
        sum=0;
        for(j=0;j<n;j++)
            sum+=ps[j].score[i];
        printf("第%d门课程的平均成绩为：%.2f\n",i+1,sum/n);
    }
}
void output(student *ps,int n);
void cptmaxscore(student *ps,int n)
{
    student *ps2=ps;
    float sum,max=0;
    int i;
    float *pn=(float *)malloc(n*sizeof(int));
    float *pn2=pn;
    student *pos;
    while(ps<ps2+n)
    {
        sum=0;
        for(i=0;i<3;i++)
            sum+=ps->score[i];
        *pn=sum;
        if(sum>max)
        {
            max=sum;
            pos=ps;
        }
        ps++;
        pn++;
    }
    printf("总成绩最高的学生信息：\n");
    output(pos,1);
}
void output(student * ps,int n)
{
    student *ps2=ps;
    while(ps<ps2+n)
    {
        printf("学号:%s\t姓名:%s\t性别:%s\n",ps->id,ps->name,ps->sex);
        printf("各科成绩为:c语言=%.2f\t高数=%.2f\t英语=%.2f\n",ps->score[0],ps->score[1],ps->score[2]);
        putchar('\n');
        ps++;
    }
}
void sort(student *ps,int n)
{
    int i,j,k;
    student t;
    for(i=0;i<n-1;i++)
    {
        k=i;
        for(j=i+1;j<n;j++)
        {
            if(ps[j].score[0]>ps[k].score[0])
                k=j;
        }
        if(k!=j)
        {
            t=ps[i];
            ps[i]=ps[k];
            ps[k]=t;
        }
    }
}
int mian()
{
    student stu[5]={
    {"001","jack","f",50,50,50},
    {"002","rose","m",60,60,60},
    {"003","lucy","m",90,90,90},
    {"004","lily","m",30,30,30},
    {"005","jime","f",80,80,80}
    };
    printf("课程的平均成绩如下:\n");
    cptcourseavg(stu,5);
    printf("\n总成绩最高的学生信息如下：");
    cptmaxscore(stu,5);
    printf("\n按c语言从高到低的顺序为：\n");
    sort(stu,5);
    output(stu,5);
    return 0;
}

我也好累啊

唉，main在哪呢？

                 .

你可以笨死了

                  我又不是故意的。。。

你是特意的。。！！！