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