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!
*     **  ** ***     *
* * **  *
{
 *    *****  *  ***  *  * *
 *  ***  **   ** ***** * *
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