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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 **** * *  ** *** *****        *     **    * **** **** ** * *** **** ** *  ****  ****** **    *    * *    ** *        
 * *****  * ****    *** * **  ***  *  *** ****  ** *    
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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