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