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