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