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