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