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