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