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