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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* **    * * * *  **** *   * *  ** * ******* * *
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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;
    *    *   *    ** * ******* **  *  ***  **   *  **
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 ***  ***  *  *** *** *****  *   ** **     *     * **  ** ***     **               *
    *****  * *** ***   *     * * * **    ** ** *    ** **  *  *  *   ** *****  *    * ***** * * ** ** * **        
 * * ** *    * *  *** ****     * *      * ******    *  
 *    *    ***** ** ** ****  * **** * *     ** *    ** *  * **   *     * *** * * *** *** *  ;
 *  ****     *** * ** ** **** 
  **  *     **    * ** *  ** * *  * 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