Updated ass7 usage.

modsim/ass2/q7.c

-/*
- * Usage: ./q7 [ generations [ max_age ] ]
- */
-
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
@@ -87,14 +83,17 @@ void sequence_old(int n) {
 }
 
 int main(int argc, char *argv[]) {
-    int max_age = 0, generations = 10;
-
-    if( argc > 1 ) {
-        generations = atoi(argv[1]);
+    int max_age = 0, generations;
 
-        if( argc > 2 )
-            max_age = atoi(argv[2]);
+    if( argc < 2 ) {
+        printf("Usage: %s GENERATIONS [ MAX_AGE ]\n", argv[0]);
+        return 1;
     }
 
+    generations = atoi(argv[1]);
+
+    if( argc > 2 )
+        max_age = atoi(argv[2]);
+
     sequence(generations, max_age);
 }