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()
{
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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