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