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