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