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