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