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()
{
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*  * *   ** **  **  *** **   * ******    *  *** ****  * ***  **  * **** * **  *     ** *            
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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