NOT WORKING CIN NOT WORKING GETLINE NOT WORKING THANKS R

***NOT WORKING - CIN NOT WORKING - GETLINE NOT WORKING - THANKS - READING IN A SENTENCE OF USER SELECTED SIZE THANKS C++

#include <iostream>
#include <cctype>
#include <cstring>
#include <cstdlib>
#include <iomanip>
using namespace std;

void displaymenu();
int count_vowels(char *, int);

int main()
{
    int Size;
    cout << \"Enter size of sentence: \" << endl;
    cin >> Size;

    char phrase[Size];
    int num_vowels =0;
    //Input a string

    cout << \"Enter a sentence : .................\";
    cin.getline(phrase, Size);
    cout << \"/......................../\" << endl;
    cout << \"Your sentence : .............\ \";
    cout << phrase << endl;

    char choice;
    do
    {

        displaymenu();
        cin >> choice;
        switch(choice)
        {
        case \'A\':
        case \'a\':

            cout << \"Count the number of vowels in the string: \" << endl;
            num_vowels =count_vowels(phrase, Size);;

            cout << \"The number of vowels: .................... \" << num_vowels << endl;

        break;

        default:
            {
                cout << \"You didn\'t enter A,B,C,D, or E: Please re-start program\" << endl;
            }

        }

    }while(choice == \'D\' || choice <= \'F\');

    return 0;
}
void displaymenu()
{
    cout << \"/......................../\" << endl;
    cout << \"Menu:\" << endl;
    cout << \"Enter A: Count the number of vowels in the string: \" << endl;
    cout << \"Enter B: Count the number of consonants in the string: \" << endl;
    cout << \"Enter C: Count Both the vowels and consonants in the string: \" << endl;
    cout << \"Enter D: Enter another string: \" << endl;
    cout << \"Enter E: Exit the program: \" << endl;
}
int count_vowels(char *charptr, int amount) //function
{

int counter = 0;
while(*charptr!=\'\\0\')
           {
             if(*charptr == \'a\' || *charptr == \'e\' || *charptr == \'i\' || *charptr == \'o\' || *charptr == \'u\')
                {

                    counter++;
                    charptr++;
                }
           }

            return counter;
   }

Solution

I have debug your code at my end it is working fine,.

Please run your code on online compiler http://cpp.sh/.

Please let us know where are running your code.