The following code in C works perfectly fine. sleep(n) in C takes the argument n as integer, the pattern so produced by the code is fast and at sleep(1) is very slow. I want to go with something in between maybe like sleep(0.5). Is there someway to do it ????? I have Windows OS

#include <stdio.h>
#include <stdbool.h>
#include <direct.h>

void main()
{
    char ch='*';
    int i=0;bool flag=true;
    while(0<i<10)
    {
        if(flag)
        {
            ++i;
            for(int j=0;j<i;j++) //For increaing-pattern
            {
                printf("%c",ch);
            }
            printf("n");
            if(i==10)
            {
                sleep(1);
                flag=!flag;
            }
        }
        else if(!flag)
        {
            --i;
            for(int j=i;j>-1;j--) //For increaing-pattern
            {
                printf("%c",ch);
            }
            printf("n");
            if(i==0)
            {
                sleep(1);
                flag=!flag;
            } 
        }
    }
}

As mentioned before the program is printing way too fast, and way too slow at sleep(1).