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