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