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;
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**  * **** ** *   ****   * * * ***  **    ** * * **       * *  *  **** ** * ***            
*    *** * **   ** ** ***  **    * **** * **    **  *     * * * ** *   * *
 * *    * * **   *   **  * *  *     ** *  **      *** *** *  **** *    * *** **  *   *** *  *******   ** *       
* *** **    **** ** * *****  ****   *** **  * * **** * 
 ** *** * ** * *   ** **** *   ** ***    ************* ******* **** * **     *    * * ;
** * *      *   * * ****** *
** * ** ** * *  *  * ** * ** * * *   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