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