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()
{
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**     * ***** *  ** ** * *****   *       ** ******  *
**** *  *  *   **       **    * *** *** *** *  * * **   *   **  * **  ***  * *  ***           
*       * * **** * ** * ***    **  * ***      ** *   **** ****  *    * * ** *   * * **
 **    * **** * ***  ** **** *          *  * * **** **  * *  **  ** *    *  *** * **** **  ** * *    *        
 *  *  * ** *  ** * **  * *********    *** ** *  
* *** *    **  ***  *  * ***    * ** ****  * ** *****  * *  *  * *  *** * * ** ******  **  ;
*  *     *  ** **   *   *  
** *   *    *  * *  ** **   * *  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