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()
{
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   *  * **   ****    ** ***    *          ** *
** *  *  * *      * * *     *   *   **** ** ** *  *      * *     ** *   *    **    *   * * **            
*** * *    **    **          * ** *    *   * *   *  *****  *  *  **** **** ** ***
****  *  ***    ****   ** * * * ** ***      * ** *      *  * ** * **  * *   *   *******  *    ** * *   **        
 *    *  ***  * *  *   **  *** **     *** *    ***  *
*  *   **** *** * * * * *     *    ** * *  **  * * *** *  * *  ******    * ** *     ** * **    ;
 * * * ** *  ***   ** *  
  **** * *  * ** ***** ** *         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