fix nonsense input, also use cc and -O3

2 files changed, 15 insertions, 14 deletions

diff --git a/Makefile b/Makefile
index 54ab42c..3b15937 100755
--- a/Makefile
+++ b/Makefile
@@ -2,9 +2,9 @@
 
 PREFIX = /usr/local
 
-CFLAGS   = -std=c99 -pedantic -Wall -Wno-deprecated-declarations -Os
+CFLAGS   = -std=c99 -pedantic -Wall -Wno-deprecated-declarations -O3
 
-CC = gcc
+CC = cc
 
 SRC = main.c
 
diff --git a/main.c b/main.c
index 7e289a3..2b90d43 100644
--- a/main.c
+++ b/main.c
@@ -1,25 +1,26 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-void PrintHelp(void) {
+int print_help(void) {
     printf("Usage: collatz <number>"
            "\nMade by samuel@yakubos.org\n\n");
+    return 1;
 }
 
 int main(int argc, char *argv[]) {
-    if ( argc < 2 || argc > 2) {
-        PrintHelp();
-        return 1;
-    }
+    if ( argc < 2 || argc > 2) return print_help();
+
     char *endptr;
-    long int num;
-    int  steps = 0;
-    num = strtol(argv[1], &endptr, 10);
+    int  int_number = strtol(argv[1], &endptr, 10);
 
-    printf("%li\n", num);
-    while ( num > 1 ) {
-        num = ( num & 1 ) ? num * 3 + 1 : num / 2;
-        printf("%li\n", num);
+    /* check the number for nonsense */
+    if ( int_number <= 0 ) return print_help();
+    unsigned long long long_num = int_number;
+
+    int  steps = 0;
+    while ( long_num > 1 ) {
+        long_num = ( long_num & 1 ) ? long_num * 3 + 1 : long_num / 2;
+        printf("%llu\n", long_num);
         steps++;
     }