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