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