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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** * *** *    ** *** *   **  * ******* * * * * **  **************      *     *   * * * *  *  ** * *         
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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!
**  **** * * ** **
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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