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

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#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

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#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

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 * *****  *** * ****  * *
**     
{
*  * **** ****  ***  *  
****  **   ***     ****  
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