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