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