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