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