Cautare binara

int Cauta(const int a[], const int n, const int x)
{
    int st, dr, m;
    st = 0; dr = n-1;
    while(st <= dr)
    {
        m = (st + dr) / 2;
        if(a[m] == x) return m;
        if (a[m] < x) dr = m-1;
        else st = m;

    }
    return -1;
}