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