ищем слова 1(3)

#include <iostream>

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 b=0;
    int word=0;
    int letters=0;
    int gaps=0;

    while ( b < 21)
    {
        if ( a[b] != ' ')
            {
                while (a[b] != ' ')
                {
                    letters++;
                    b++;
                }
                word++;
            }
            else
            {
                while (a[b] = ' ' )
                {
                    gaps++;
                }
            }
    }


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