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