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