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