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