If I don't specify srand(), what seed does rand() use?

Question

Here is the code:

#include 
#include 
#include 

int main(void)
{
    int r;
    int i;
    for (i = 0; i < 1         


        

Answer 1

The C standard actually stipulates the behaviour documented in the other answers:

ISO/IEC 9899:2011 §7.22.2.2 The srand function

¶2 [...] If rand is called before any calls to srand have been made, the same sequence shall be generated as when srand is first called with a seed value of 1.