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;
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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