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()
{
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*  * * *    **** ** ****  ** *    ** ** * *** *  ** * ** * ** ** **      *  * **    * **            
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***  ****** **  *******  ** **  *** *   ** *  **      ***    *   ** *  * **  * * * * *  ** *  ******             
   * ** *** *** * * *  * **** * * * *  *     *** 
*** ***  ***  ***  **** **  *   * *** *  *  *       * **  ***  * * **  **  *  * *** ** * ;
 *  **  ** * * ***** * *    ***
  ****** *   *****  ****** 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