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;
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 ***    **      ******* *      ****  * *** * *  * ***** ** * * *     *  * *  *** *
 * ** * ***  * *     *   *  *       *******  *    * *   * *** *    ** * * ******   *    ** **  **** * *       
       * ** ** * * ***   * * ** * *    * **    * ** *   *  * 
*  *   *  * *   **    **** ** *****  *** * *   ** *****  **  * * **** *   ** * * *  * ** * ;
*   *      *  *   * ** *    
    * *  * * * * *** ** ** ** 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