3 files changed, 37 insertions, 0 deletions

diff --git a/mat/euler/3/Makefile b/mat/euler/3/Makefile
new file mode 100644
index 0000000..156bc0d
--- /dev/null
+++ b/mat/euler/3/Makefile
@@ -0,0 +1,2 @@
+default:
+	gcc prog.c -lm
diff --git a/mat/euler/3/a.out b/mat/euler/3/a.out
new file mode 100755
index 0000000..1cb7d86
--- /dev/null
+++ b/mat/euler/3/a.out
diff --git a/mat/euler/3/prog.c b/mat/euler/3/prog.c
new file mode 100644
index 0000000..753b1fb
--- /dev/null
+++ b/mat/euler/3/prog.c
@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+int jePrastevilo(int u) {
+	if (u <= 1)
+		return 0;
+	if (u == 2)
+		return 1;
+	for (int i = 2; i <= ceil(sqrt(u)); i++)
+		if (u % i == 0)
+			return 0;
+	return 1;
+}
+int main (int argc, char ** argv) {
+	if (argc != 1+1) {
+		fprintf(stderr, "uporaba: %s <stevilo>\nprimer: %s 600851475143\n", argv[0], argv[0]);
+		return 1;
+	}
+	unsigned long long p = 0;
+	unsigned long long n = strtoll(argv[1], NULL, 10);
+	unsigned long long i = 1;
+	unsigned long long k = ceil(sqrt(n))+1;
+	while (i < k) {
+		i = i + 2;
+		if (!jePrastevilo(i))
+			continue;
+		if (n % i == 0)
+			p = i;
+		if (1==1) {
+			fprintf(stderr, "%lld, i = %lld, k = %lld, n = %lld\r", (i/k)*100, i,k,n);
+		}
+	}
+	fprintf(stdout, "\rkonec. našel največje praštevilo %lld: %lld\n", n, p);
+	return 0;
+}