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