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

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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