C/C++调用系统函数API显示系统时间

计算机操作系统上课作业：
C/C++调用系统函数API显示系统时间，代码展示如下
[code]
#include <stdio.h>
#include <math.h>-
#include <dos.h>
#include <time.h>
#include <windows.h>
#include <conio.h>

void main()
{
tm *curtime;
time_t t;
do
{
t=time(NULL);
curtime=localtime(&t);/*得到当前系统时间*/
printf("*********************************************\n");
printf("** This is a simple clock program.         **\n");
printf("**                                         **\n");
printf("*********************************************\n");
printf("The current time is:\n");
if((float)curtime->tm_hour<=12)         /*午前的处理*/
{
printf("AM ");
if((float)curtime->tm_hour<10)
printf("0");   /*十点之前在小时数前加零*/
printf("%.0f:",(float)curtime->tm_hour);
}
else         /*午后的处理*/
{
printf("PM ");
if((float)curtime->tm_hour-12<10)
printf("0");
printf("%.0f:",(float)curtime->tm_hour-12);
}
if((float)curtime->tm_min<10)
printf("0");
printf("%.0f:",(float)curtime->tm_min);
if((float)curtime->tm_sec<10)
printf("0");
printf("%.0f",(float)curtime->tm_sec);
printf("\n");
printf("\n");
printf("\n");
printf("\n");
printf("\n");
printf("\n");
Sleep(1);      /*延时一秒后刷新*/
system("cls");
}while(1);
char a[512];
unsigned long size=512;
GetComputerName(a,&size);
printf("The computer's name is:/n ");
printf("%s",a);
printf("/n");
}