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