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