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