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