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