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#include <math.h>
#include <stdio.h>
#include <time.h>
#include <stc/crandom.h>
#include <stc/cmap.h>
using_cmap(ic, uint64_t, uint8_t);
static uint64_t seed = 12345;
static void test_repeats(void)
{
enum {BITS = 46, BITS_TEST = BITS/2 + 2};
const static uint64_t N = 1ull << BITS_TEST;
const static uint64_t mask = (1ull << BITS) - 1;
printf("birthday paradox: value range: 2^%d, testing repeats of 2^%d values\n", BITS, BITS_TEST);
stc64_t rng = stc64_init(seed);
cmap_ic m = cmap_ic_init();
cmap_ic_reserve(&m, N);
c_forrange (i, N) {
uint64_t k = stc64_rand(&rng) & mask;
int v = cmap_ic_emplace(&m, k, 0).ref->second += 1;
if (v > 1) printf("repeated value %llx (%d) at 2^%d\n", k, v, (int) log2(i));
}
}
using_cmap(x, uint32_t, uint64_t);
void test_distribution(void)
{
enum {BITS = 26};
printf("distribution test: 2^%d values\n", BITS);
stc64_t rng = stc64_init(seed);
const size_t N = 1ull << BITS ;
cmap_x map = cmap_x_init();
c_forrange (N) {
uint64_t k = stc64_rand(&rng);
cmap_x_emplace(&map, k & 0xf, 0).ref->second += 1;
}
uint64_t sum = 0;
c_foreach (i, cmap_x, map) sum += i.ref->second;
sum /= map.size;
c_foreach (i, cmap_x, map)
printf("%4u: %zu - %zu: %11.8f\n", i.ref->first, i.ref->second, sum, (1 - (double) i.ref->second / sum));
}
int main()
{
seed = time(NULL);
test_distribution();
test_repeats();
}
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