1 files changed, 45 insertions, 0 deletions
diff --git a/misc/examples/algorithms/random.c b/misc/examples/algorithms/random.c
new file mode 100644
index 00000000..9522c16d
--- /dev/null
+++ b/misc/examples/algorithms/random.c
@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <time.h>
+#include <stc/crand.h>
+
+int main(void)
+{
+    const long long N = 10000000;
+    const uint64_t seed = (uint64_t)time(NULL), range = 1000000;
+    crand_t rng = crand_init(seed);
+
+    long long 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, %lld, avg: %f\n",
+           (double)diff/(double)CLOCKS_PER_SEC, N, (double)(sum/N));
+
+    crand_uniform_t dist1 = crand_uniform_init(0, range);
+    rng = crand_init(seed);
+    sum = 0;
+    before = clock();
+    c_forrange (N)  {
+        sum += crand_uniform(&rng, &dist1); // unbiased
+    }
+    diff = clock() - before;
+    printf("unbiased 0-%lld\t: %f secs, %lld, avg: %f\n",
+            (long long)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, %lld, avg: %f\n",
+            (long long)range, (double)diff/CLOCKS_PER_SEC, N, (double)(sum/N));
+
+}