From 598834255fd39f085286e7d75c46a6f012d22e6b Mon Sep 17 00:00:00 2001
From: Quinn <quinnthepigeon@proton.me>
Date: Thu, 19 Jun 2025 16:40:54 +0200
Subject: [PATCH] optimize some more by using /dev/random

---
 src/main.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/src/main.c b/src/main.c
index 7135a15..6ebc07d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,10 +1,9 @@
-#include <bits/time.h>
 #include <errno.h>
 #include <limits.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <sys/types.h>
+#include <sys/random.h>
 #include <time.h>
 
 #define error(ret, s, ...)                             \
@@ -17,14 +16,8 @@ typedef unsigned long long ull;
 
 
 int main(int argc, char** argv) {
-	// get the current time to set as the seed
-	struct timespec ts;
-	clock_gettime(CLOCK_MONOTONIC, &ts);
-	srandom(ts.tv_nsec);
-
 	// return the result if no input
-	if (argc <= 1)
-		return printf("%s\n", (rand() & 1) ? "heads" : "tails");
+	if (argc <= 1) return printf("%s\n", (rand() & 1) ? "heads" : "tails");
 
 	// loop through arguments
 	for (unsigned i = 1; i < (unsigned)argc; ++i) {
@@ -37,18 +30,20 @@ int main(int argc, char** argv) {
 		ull headsc = 0; // amount of heads
 		ull tailsc = 0; // amount of tails
 
-		while (c >= 31) {
-			c -= 31;
-			long n = random();                // generate a random number for this batch
-			int cnt = __builtin_popcountl(n); // counts the set bits
+		while (c >= (sizeof(ull) * 8)) {
+			c -= (sizeof(ull) * 8);
+			ull n;
+			getrandom(&n, sizeof(ull), GRND_INSECURE);
+			int cnt = __builtin_popcountll(n); // counts the set bits
 			headsc += cnt;
 			tailsc += 31 - cnt;
 		}
 
 		if (c > 0) {
-			long n = random();
+			long n;
+			getrandom(&n, sizeof(ull), GRND_INSECURE);
 			long msk = (1 << c) - 1;
-			int cnt = __builtin_popcountl(n & msk);
+			int cnt = __builtin_popcountll(n & msk);
 			headsc += cnt;
 			tailsc += c - cnt;
 		}