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#include <stdio.h>
#include <time.h>
#include <stc/crand.h>
int main(void)
{
const int N = 10000000;
const uint64_t seed = (uint64_t)time(NULL), range = 1000000;
crand_t rng = crand_init(seed);
int64_t sum;
clock_t diff, before;
printf("Compare speed of full and unbiased ranged random numbers...\n");
sum = 0;
before = clock();
c_forrange (N) {
sum += (uint32_t)crand_u64(&rng);
}
diff = clock() - before;
printf("full range\t\t: %f secs, %d, avg: %f\n",
(double)diff/CLOCKS_PER_SEC, N, (double)sum/N);
crand_unif_t dist1 = crand_unif_init(0, range);
rng = crand_init(seed);
sum = 0;
before = clock();
c_forrange (N) {
sum += crand_unif(&rng, &dist1); // unbiased
}
diff = clock() - before;
printf("unbiased 0-%" PRIu64 "\t: %f secs, %d, avg: %f\n",
range, (double)diff/CLOCKS_PER_SEC, N, (double)sum/N);
sum = 0;
rng = crand_init(seed);
before = clock();
c_forrange (N) {
sum += (int64_t)(crand_u64(&rng) % (range + 1)); // biased
}
diff = clock() - before;
printf("biased 0-%" PRIu64 " \t: %f secs, %d, avg: %f\n",
range, (double)diff/CLOCKS_PER_SEC, N, (double)sum/N);
}
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