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