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