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