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