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