随机 function 总是返回 1

Question

My random function always returns a "1" rather than... anything
It is supposed to return a "0" or "1"

int rnd() {
    unsigned int num0 = rand();
    if(num0 < 32767.5) {return 0;}
    if(num0 > 32767.5) {return 1;}
}

int chk;
bool _True = true;

int main(void) {
    while(_True) {
        chk = rnd();
        printf("%i\n", chk);
        //if(chk == 1) {printf("%i\n", chk); _True = false;}
        //if(chk == 0) {printf("%i\n", chk); _True = false;}
    }
}

Answer 1

First, rand() gives a pseudo-random number based on a seed. If you don't call srand() before rand(), you will get the same sequence of random numbers every time you run the program.

Second, the rand() function returns a pseudo-random number in the range of 0 to RAND_MAX.

RAND_MAX is a constant whose default value may vary between implementations but it is guaranteed to be at least 32767.

You seem to be assuming RAND_MAX is twice 32767.5?

I would suggest calling srand() first and then testing versus RAND_MAX / 2, or setting your value to rand() % 2 instead.

(You could have determined such by printing what rand() was returning, and/or by looking up the documentation of rand().)