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