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