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