10-19 Exercise 3: Prints the number with its digits reversed

Question

Write a program that input four-digit number, then prints the number with its digits reversed .

寫一個輸入4位數字，反轉輸出這個數字的值

Example input: 

5455

Example output:

5545

Example input: 

5400

Example output:

45

Answer 1

Hidden content!
#include <stdlib.h>

using namespace std;

int main()
{
*  * **  *  *       *  ** *  x;
*  ** * *** ***** ** ** * ** * * *  *    ** **
 * *   **   ****** **  **     *     *    **   * *  *    **   *    **    *****    *   **             
 * **** *  *  * *   * ****    ***  * * *  ******* ***  **   ** * **  *    **  
 * **     * * ** * * *  * ** ***  *****  ***  ***** *  * * * *    *  **   *  * **  *    * * *  **  ****  ** ******          
 ****   * * ****    ** **** *   **     *   *     *  *
* **  ***** ***  *    *** **   *  ****  *   *    * ** *** * *** **** * * * * *****     ***** ;
****   ***    ***  **     ** 
 ** **   *   *  *****  *  **   ** 0;
}

Comments

prog.c:3:1: error: unknown type name 'using'
 using namespace std;
 ^~~~~
prog.c:3:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
 using namespace std;
                 ^~~
prog.c: In function 'main':
prog.c:7:5: error: unknown type name 'string'
     string x;
     ^~~~~~
prog.c:8:11: error: 'cin' undeclared (first use in this function)
     while(cin>>x){
           ^~~
prog.c:8:11: note: each undeclared identifier is reported only once for each function it appears in
prog.c:10:24: error: request for member 'length' in something not a structure or union
         for(int i=0;i<x.length();i++){
                        ^
prog.c:11:22: error: request for member 'length' in something not a structure or union
             re[i]=x[x.length()-i-1];
                      ^
prog.c:13:9: error: 'cout' undeclared (first use in this function)
         cout<<atoi(re)<<endl ;
         ^~~~
prog.c:13:25: error: 'endl' undeclared (first use in this function)
         cout<<atoi(re)<<endl ;
                         ^~~~

Answer 2

Hidden content!
#include <iostream>
#include  ** ***** * 

using namespace std;

int main()
{
*  * ** * **   ***  *   ** x;
    * *** * * **  *   * * ***       *  **  *  **  *
 *  * * *    ** *  ***  *** *  **    * * **** ** *  *** ** **   ** * * ******* **           
**** *   *     * * ***   * ** * ** ****** * *  *   * *** ****  *****  
** ******      *  *** *  **     **** ***       *  *    *** * *   * *    *   **   **** *   *****  *  ** * **         
 * ** * *** **  **   *  * ** ** *         *** *    *
 *  * *  ***  *** *  **  **   ***   ** * * *     *** ** ***** ** *      *****      ****  ;
 *** ****      * *** *  ***
  * *   *** **   *** *  *** * ** * 0;
}

Comments

prog.c:1:20: fatal error: iostream: No such file or directory
 #include <iostream>
                    ^
compilation terminated.

Answer 3

Hidden content!
** ** ** **  *** *   
   *   
{
**   **  ** *    * *  * 
** *   *** *  *** * *  * * *  
a = *   * 
*** *      * * ** **   * =    * 

c = **  
 *  ** **** * * *** = * *

e = **** 
*  *****  *** * *** = **

g =   *
*    *  **  **** * ***  = **

*** = c;
* =  
 =    

* *  = *
  =  
* = ** 


 ** =  * ** *    *   
****  * ** ***  ** **  *

* **    
}

Comments

prog.c: In function 'main':
prog.c:4:19: error: variable 'h' set but not used [-Werror=unused-but-set-variable]
 int a,b,c,d,e,f,g,h,v,swap,temp,sum;
                   ^
cc1: all warnings being treated as errors

Answer 4

Hidden content!
  ***   
 
    *   *** ***** *  **  
  *  * ** **  * * * ***  
a = *** 
***** * **  *   ** *   ** = **  **

c = **
  * * * * *      ******* = * *

e = ****
***  *  *  ** ***  *  * =  

g =    
       * *   ***** = ** 

 ** =  *
 * = *
 = * *

   * = *
 * =  
 = * 


*** = * * **   *** 
** ** * *   *** * 

 ** * 
**

Comments

prog.c: In function 'main':
prog.c:4:1: error: implicit declaration of function 'scanf' [-Werror=implicit-function-declaration]
 scanf("%d",&v);
 ^~~~~
prog.c:4:1: error: incompatible implicit declaration of built-in function 'scanf' [-Werror]
prog.c:4:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
prog.c:27:1: error: implicit declaration of function 'printf' [-Werror=implicit-function-declaration]
 printf("%d",sum);
 ^~~~~~
prog.c:27:1: error: incompatible implicit declaration of built-in function 'printf' [-Werror]
prog.c:27:1: note: include '<stdio.h>' or provide a declaration of 'printf'
prog.c:3:19: error: variable 'h' set but not used [-Werror=unused-but-set-variable]
 int a,b,c,d,e,f,g,h,v,swap,temp,sum;
                   ^
cc1: all warnings being treated as errors