还是不太明白或与那里是怎么回事，一知半解，等以后学得更深了，再回来看就懂了。老师的课程真好~

代码如下：
  1 #include <stdio.h>
  2 #include <stdlib.h>
  3 #include <time.h>
  4
  5 //create a list that can have 1001 number.
  6 //Get "egmentation fault (core dumped)" error when I enter 1008 .
  7 //Don't know why it's 1008 not 1001.
  8 int f[1001];
  9
 10 // main function
 11 int main(){
 12
 13 // create an int as n
 14 int n;
 15
 16 // input a number as n
 17 scanf("%d", &n);
 18
 19 // set the first number in the list to 0
 20 f[0] = 0;
 21
 22 // insert how many 1 each number has to the list
 23 for (int i = 1; i <= n; i++) {
 24 f[i] = f[i & (i - 1)] + 1;
 25 }
 26
 27 // print the resule in the list one by one
 28 // you have to use a loop to output element in a list in C
 29 // you can just use 'printf("%d", f[i]);', but it will get an extra ' ' at the begining.
 30 for (int i = 1; i <= n; i++) {
 31 if (i != 1) printf(" "); //aviod the first space
 32 printf("%d", f[i]);
 33 }
 34
 35 // print a new line
 36 printf("\n");
 37
 38 // return 0
 39 return 0;
 40 }
 41

vim test10.cpp
#include<stdio.h>

int main(){
int a;
sizeof(a); // 计算 a 变量占用字节数量
sizeof(int); // 计算一个整型元素占用字节数量
return 0;
}
gcc test10.cpp
./a.out
老师，我进行了上述操作，为什么屏幕上面没有任何回应呀？

vim test09.cpp
#include<stdio.h>
int main(){
int n, arr[1000];
scanf("%d", &n);
for (int i = 0; i < n; i++) scanf("%d", &arr[i]);
return 0;
}
gcc test09.cpp
./a.out
这是我的操作，请问老师下面我应该打什么命令呀？