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