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