c语言动态时钟怎么更新数字？想找一个代码研究一下，不要求精准，<20行代码的那种

/简单动态时钟 2021.7.25 葛保师/

#include"stdio.h"

int main(void)
{

int second,minutes,hour;
printf("时间输入:(时 分 秒)");
scanf("%2d%2d%2d",&second,&minutes,&hour);
while(second<0||second>60||minutes<0||minutes>60||hour<0||hour>24)
{
    while(getchar()!='\n');
    printf("时间输入(时 分 秒):");
    scanf("%2d:%2d:%2d",&second,&minutes,&hour);
}
while (1)
{
    for (int i = 0; i <= 100; i++)
    for(int j=0;j<100000;j++);
    if (second == 60)
    {
           second = 0;
        minutes++;
    }
        if (minutes == 60)
    {
           minutes = 0;
         hour++;
    }
    if (hour == 24)
    {
        hour = 0;
    }
    printf("%2d:%2d:%2d\r",hour,minutes,second);
}
return 0;

}

你写的不是？