ищем слова 1(8)

#include <iostream>
#include <cstring>

using namespace std;

int main()
{
    cout << "you can enter 20 symbols" << endl;
    char a[21];
    cin.getline(a,21);
    cout << "these symbols take part in the test" << endl;
    cout << a << endl;

    int letters, gaps, word, b,  num;
    letters = 0;
    gaps = 0 ;
    word = 0;
    b = 0;
    num = strlen (a);



     while ( b < num)
    {

                if (b + 1 == num and a[b] == ' ')
                {
                    break;
                }

                if ( a[b] != ' ')
                {
                    b++;
                    letters++;
                }

                if ( a[b] == ' ')
                {
                    b++;
                    gaps++;
                }

    }

    b=0;
     while ( b < num)
    {
        if ( a[b] != ' ' )
        {

            while ( a[b] != ' ' )
            {
                b++;
            }
            word++;
        }
        b++;
    }



    cout << "these symbols have   " <<  word <<  "  words" ;
    cout << endl << letters << "    letters" ;
    cout << endl << gaps << "   gaps";
}