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