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