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