Why does my srand(time(NULL)) function generate the same number every time in c?

So I was creating a program that would call a function and return 0 or 1 (0 meaning tails and 1 meaning heads) and then use that to print the outcome of 100 flips.

It seemed simple enough thinking I could use srand(time(NULL)) to seed rand() with constantly varying seeds. Here was my first crack.

#include <stdio.h>
#include <stdlib.h>
int flip();


int main(void) {

    int heads = 0;
    int tails = 0;

    for (short int count = 1; count <= 100; ++count) {

        int number = flip();

        if (number == 0) {
            printf("%s", "Tails");
            ++tails;
        }
        else if (number == 1) {
            printf_s("%s", "Heads");
            ++heads;
        }

    }//end for
    printf_s("\n%d Tails\n", tails);
    printf_s("%d Heads", heads);
}//end main

int flip(void) {

    srand(time(NULL));
    int number = (int)rand();
    printf("%d", number%2);
    return number%2;
}//end flip

I would run the program and my rand() value would always be a five digit integer repeated in each iteration of the for statement (i.e 15367, 15745, or 15943).

I messed around until I discovered changing srand(time(NULL)) to srand(time(NULL)*time(NULL)/rand()) did the trick.

My only thought is that the time between each for iteration is so small the the time(NULL) part of the srand() function doesn't change enough to feed a different seed value.

I also tried srand(time(NULL)/rand()), however, this produced the same result (52 heads 48 tails) every time I ran the program (20+times); however, the rand() values were all different from each other.

I do not know why these things happened, or why the final srand(time(NULL)*time(NULL)/rand()) function worked, and I would love it if someone could explain!