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