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