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