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