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