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()
{
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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!
****  ** ***  *  
* *  *  
{
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 *** ** ***** ****   * * *
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