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