输入一个10进制，输入2进制

 1 #define _CRT_SECURE_NO_WARNINGS
 2 
 3 #include<stdio.h>
 4 #include<windows.h>
 5 
 6 void change2(int num);
 7 
 8 main()
 9 {
10     int num;
11     scanf("%d", &num);
12 
13     printf("num=%d\n", num);
14 
15     change2(num);
16 
17     system("pause");
18 }
19 
20 void change2(int num)
21 {
22     if (num == 0)
23     {
24         return;
25     }
26     else
27     {
28         change2(num / 2);
29         printf("%d", num % 2);
30     }
31 }