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