程序代码：

#include"stdio.h"
double fun(int n);
double f(int n);
int mian(){
    int i;
    printf("n e\n");
    printf("-------------\n");
    for(i=0;i<10;i++){
        printf("%d %.9lf\n",i,fun(i));
    }
    return 0;
}
double fun(int n){
    int i;
    double s=0.0;
    for(i=1;i<=n;i++){
        s+=f(i);
    }
    return s;
}
double f(int n){
    double t;
    t=1.0/n;
    return t;
}
--------------------Configuration: 1012 - Win32 Debug--------------------
Linking...
LIBCD.lib(crt0.obj) : error LNK2001: unresolved external symbol _main
Debug/1012.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

1012.exe - 1 error(s), 0 warning(s)

int mian()