Cast NSUD to double when calculating solved percentage

main.c

@@ -59,7 +59,7 @@ int main(void)
 			++solved;
 	}
 
-	double solved_pc = 1e2 * (double)solved / NSUD;
+	double solved_pc = 1e2 * (double)solved / (double)NSUD;
 	printf("Solved %u/%u (%.3lf%%)\n", solved, NSUD, solved_pc);
 
 	return EXIT_SUCCESS;