// gcc nomod.c -o nomod; ./nomod

/*
Explanation:

* rand is treated as a 32-bit fixed-point number in [0, 1) (implicitly scaled by 2³²).
* Multiplying by len scales it to [0, len).
* Shifting right by 32 bits extracts the integer part (0..len-1).

I guess I will go with decimal system for understanding this...
So lets say I have two-digit decimal numbers from 00..99 this
means that multiplying two of these should always fit in a
four-digit decimal number isn't  it? from 0000..9999 because
99*99 is 9801 so it fits in and its the biggest possible pairs
to multiply.

Now lets have a "len" number with also at most two digits, let
it be 20 - this will be our "modulus". Lets multiply a random
two-digit number with this. We get lets say 71*20 which is 1400.
Shifting two digits to the right it becomes 14. If I do 99*20
(which is biggest) I get 1980 so when shiften decimally it
becomes 19 (which is again smaller than 20).

It looks like the random numbers from 00..99 indeed start to map
onto 00..19 in this case. Very fascinating! Just avoid cryptin'
*/

#include <stdio.h>
#include <stdint.h>
#include "fastrand.h"

int main() {
	uint32_t from = 12;
	uint32_t to = 32;
	int n = 30;

	rand_state rs = init_rand();
	for(int i = 0; i < n; ++i) {
		uint32_t choice = rand_between(&rs, from, to);
		printf("rand [%u, %u): %u\n", from, to, choice);
	}

	return 0;
}