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