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