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