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