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