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