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