[求]C语言倒计时程序

编译器: Default compiler
执行 gcc.exe...
gcc.exe "C:\Documents and Settings\Administrator\桌面\未命名2.c" -o "C:\Documents and Settings\Administrator\桌面\未命名2.exe" -ansi -traditional-cpp -w -g3 -fmessage-length=0 -I"C:\Program Files\DEV-CPP\include" -L"C:\Program Files\DEV-CPP\Lib" -g3 -fmessage-length=0
C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cc8Ueaaa.o(.text+0x4f): In function `main':
C:/Documents and Settings/Administrator/桌面/未命名2.c:10: undefined reference to `clrscr'
C:\DOCUME~1\ADMINI~1\LOCALS~1\Temp/cc8Ueaaa.o(.text+0xca):C:/Documents and Settings/Administrator/桌面/未命名2.c:17: undefined reference to `clrscr'
collect2: ld returned 1 exit status

执行结束

pengming501 为什么编译器提示有2处错误呢？？

#include
#include
#include
int main()
{
clock_t start,end;
int n;
printf("How many seconds do you want to count? ");
scanf("%d",&n);
getchar();
system("cls");
start=end=clock();
while((n-(int)(end-start)/CLK_TCK)>=0)
{
printf("the time is: %d========",n-(int)(end-start)/CLK_TCK);
printf("%d",(int)(end-start)/CLK_TCK);
Sleep(100);
end=clock();
system("cls");
}
return 0;
}一秒一次

我试过了.还可以吧.

#include
#include
main()
{
clock_t start,end;
int n;
printf("How many seconds do you want to count? ");
scanf("%d",&n);
getchar();
clrscr();
start=end=clock();
while((n-(int)(end-start)/19)>=0)
{
printf("the time is: %d",n-(int)(end-start)/19);
sleep(1);
end=clock();
clrscr();
}
}