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