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