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