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