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