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