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