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