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