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