#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/time.h>

static inline uint64_t rotl(const uint64_t x, int k) {
	return (x << k) | (x >> (64 - k));
}

static uint64_t s[4];

uint64_t next(void) {
	const uint64_t result = s[0] + s[3];

	const uint64_t t = s[1] << 17;

	s[2] ^= s[0];
	s[3] ^= s[1];
	s[1] ^= s[2];
	s[0] ^= s[3];

	s[2] ^= t;

	s[3] = rotl(s[3], 45);

	return result;
}


static uint64_t get_system_time(void) {
	struct timeval tv;
	gettimeofday(&tv, NULL);
	return tv.tv_sec * 1000000 + tv.tv_usec;
}

int f(uint64_t *p, int l) {
	int c = 0;

	for(int i = 1; i < l; i++) {
		c += p[i] == p[i - 1];
	}

	return c;
}

int main() {
	uint64_t *p = calloc(1000000000, sizeof *p);
	for(int i = 0; i < 1000000000; i++) p[i] = next();

	for(int i = 0; i < 10; i++) {
		uint64_t start = get_system_time();
		const volatile int u = f(p, 1000000000);
		printf("%.3f\n", (get_system_time() - start) * 1E-6);
	}
}