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