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;
        * * *  *** ** *  **  ****  **   * * 
  * **  *   *** * *   ** ****   * **  *** * * *  *  *  ** * **  * *    ****  **    *           
** * *****   *****   ** * * * * *  ***     **  * *** ****  ** **    ****   **     
*  ** *** * ******* *  *    ***   **  * * * * *  *    ** *    * ***    **** *******  **** *****   * * **       
*   * **   **   *  **  * *  **** * *  * ***** **   ** *
** ******  ** *   ***** *  *  ** ** * **  **  * ** * ***** ***   *     *    **  * *** ;
   * ** ***  ****    ***** ** *
**  **  *** ***  ** *  ****  * **  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