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