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