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