vector自实现(一)

vector.h:

#ifndef __Vector__H__
#define __Vector__H__
typedef int Rank;
#define DEFAULT_CAPACITY 3

template<typename T> class Vector{
protected:
    Rank _size; int _capacity; T*_elem;
    void copyFrom(T const *A, Rank lo, Rank hi);
    void expand();
    void shrink();
    void bubbleSort(Rank lo,Rank hi);
    bool bubble(Rank lo,Rank hi);
    void mergeSort(Rank lo,Rank hi);
    void merge(Rank lo,Rank mi,Rank hi);
public:
    Vector(int c = DEFAULT_CAPACITY,int s = 0, T v = 0)
    {
        _elem = new T[_capacity = s];
        for (_size = 0; _size < s; _elem[_size++] = v);
    }
    Vector(T const *A, Rank n) { copyFrom(A, 0, n); }
    Vector(T const *A, Rank lo, Rank hi) { copyFrom(A, lo, hi); }
    Vector(Vector<T> const &V) { copyFrom(V._elem,0,V._size); }
    Vector(Vector<T> const &V, Rank lo, Rank hi) { copyFrom(V._elem, lo, hi);}
    ~Vector(){delete[]_elem;}

    Rank size() const { return _size;}
    bool empty() const { return !_size;}
    Vector<T>& operator=(Vector<T> const&);

    T&operator[](Rank r) const;

    void unsort(Rank lo,Rank hi);
    Rank find(T const& e,Rank lo,Rank hi) const;
    Rank insert(Rank r,T const& e);
    int remove(Rank lo,Rank hi);
    T remove(Rank r);
    int deduplicate();
    int disordered() const;

    int uniquify();

    void traverse(void(*)(T&));
    template<typename VST> void traverse(VST&);

    static Rank binSearch(T* A,T const& e,Rank lo,Rank hi);
    static Rank binSearch2(T* A, T const& e, Rank lo, Rank hi);
    static Rank binSearch3(T* A, T const& e, Rank lo, Rank hi);
};
#endif 

vector.cpp:

#include"Vector.h"
template<typename T>
void Vector<T>::copyFrom(T const * A, Rank lo, Rank hi)
{
    _elem = new T[_capacity=2*(hi-lo)];
    _size = 0;
    while (lo < hi)
    {
        _elem[_size++] = A[lo++];
    }
}

template<typename T>
void Vector<T>::expand()
{
    if (_size < _capacity)return;
    if (_capacity < DEFAULT_CAPACITY) { _capacity = DEFAULT_CAPACITY; }
    T*oldElem = _elem;
    _elem = new T[_capacity<<=1];
    for (int i = 0; i < _size; i++)
    {
        _elem[i] = oldElem[i];
    }
    delete[]oldElem;
}

template<typename T>
void Vector<T>::shrink()
{
    if (_capacity < DEFAULT_CAPACITY << 1)return;
    if (_size << 2 > _capacity)return;
    T *oldElem = _elem;
    _elem = new T[_capacity>>=1];
    for(int i = 0; i < _size; i++)
    {
        _elem[i] = oldElem[i];
    }
    delete[]oldElem;
}

template<typename T>
void Vector<T>::bubbleSort(Rank lo, Rank hi)
{
    while (!bubble(lo,hi--));
}

template<typename T>
bool Vector<T>::bubble(Rank lo, Rank hi)
{
    bool sorted = true;
    while (++lo < hi)
    {
        if(_elem[lo - 1] < _elem[lo])
        {
            sorted = false;
            swap(_elem[lo-1],_elem[lo]);
        }
    }
    return sorted;
}

template<typename T>
void Vector<T>::mergeSort(Rank lo, Rank hi)
{
    if (hi - lo < 2) return;
    int mi = (lo + hi) / 2;
    mergeSort(lo,mi);
    mergeSort(mi,hi);
    merge(lo,mi,hi);
}

template<typename T>
void Vector<T>::merge(Rank lo, Rank mi,Rank hi)
{
    T *A = _elem + lo;
    int lb = mi - lo;
    T* B = new T[lb];
    for (int i = 0; i < lb; i++) B[i] = A[i];
    int rb = hi - mi;
    T *C = _elem + mi;
    for (Rank i=0,int j = 0, int k = 0; (j < lb) || (k < rb);)
    {
        if ((j<lb)&&(k>rb||(B[j] < C[k])))
        {
            A[i++] = B[j++];
        }
        if ((k<rb)&&(j>lb||(C[k]<=B[j])))
            ｛
            A[i++] = C[k++];
        ｝
    }
    delete[] B;

}

template<typename T>
Vector<T>& Vector<T>::operator=(Vector<T> const & V)
{
    if (_elem) delete[]_elem;
    copyFrom(V._elem,0,V._size);
    return *this;
}

template<typename T>
T & Vector<T>::operator[](Rank r) const
{
    return _elem[r];
}

template<typename T>
void Vector<T>::unsort(Rank lo, Rank hi)
{
    T* V = _elem + lo;
    for(Rank i = hi - lo; i >= 0; i--)
    {
        swap(V[i-1] = V[rand()%i]);
    }
}

template<typename T>
Rank Vector<T>::find(T const & e, Rank lo, Rank hi) const
{
    while((lo < hi--)&&(e!=_elem[hi]));
    return hi;
}

template<typename T>
Rank Vector<T>::insert(Rank r, T const & e)
{
    expand();
    for (int i = _size; i > r; i--)
    {
        _elem[i] = _elem[i-1];
    }
    _elem[r] = e;
    _size++;
    return r;
}

template<typename T>
int Vector<T>::remove(Rank lo, Rank hi)
{
    if (lo == hi)return 0;
    while (hi < _size)
    {
        _elem[lo++] = _elem[hi++];
    }
    _size = lo;
    shrink();
    return hi - lo;
}

template<typename T>
T Vector<T>::remove(Rank r)
{
    T e = _elem[r];
    remove(r,r+1);
    return e;
}

template<typename T>
int Vector<T>::deduplicate()
{
    int oldsize = _size;
    Rank i = 1;
    while (i < _size)
    {
        (find(_elem[i], 0, _size) < 0) ? i++ : remove(i);
    }

    return oldsize-_size;

}

template<typename T>
int Vector<T>::disordered() const
{
    int n = 0;
    for (int i = 1; i < _size; i++)
    {
        if(_elem[i - 1] > _elem[i])
        {
            n++;
        }
    }
    return n;
}

template<typename T>
int Vector<T>::uniquify()
{
    Rank i = 0, j = 0;
    while (++j < _size)
    {
        if (_elem[i] != _elem[j])
        {
            _elem[++i] = _elem[j];
        }
    }
    _size = ++i;
    shrink();
    return j - i;
}

template<typename T>
Rank Vector<T>::binSearch(T * A, T const & e, Rank lo, Rank hi)
{
    while (lo < hi)
    {
        Rank mi = (lo + hi) >> 1;
        if (e > A[mi])
        {
            lo = mi+1;
        }
        else if (e < A[mi])
        {
            hi = mi;
        }
        else {
            return mi;
        }
    }
    return -1;
}

template<typename T>
Rank Vector<T>::binSearch2(T * A, T const & e, Rank lo, Rank hi)
{
    while (1 < (hi - lo))
    {
        Rank mi = (lo + hi) >> 1;
        (e < A[mi]) ? hi = mi : lo = mi;
    }
    return (e == A[lo]) ? lo : -1;
}

template<typename T>
Rank Vector<T>::binSearch3(T * A, T const & e, Rank lo, Rank hi)
{
    while (lo < hi)
    {
        Rank mi = (lo + hi) >> 1;
        (e < A[mi]) ? hi = mi : lo = mi + 1;
    }
    return --lo;
}

template<typename T>
void Vector<T>::traverse(void(*visit)(T &))
{
    for (int i = 0; i < _size; i++)
    {
        visit(_elem[i]);
    }
}

template<typename T>
template<typename VST>
void Vector<T>::traverse(VST &visit)
{
    for (int i = 0; i < _size; i++)
    {
        visit(_elem[i]);
    }
}