absllist.h

data structures, algorithms and Application书的源代码

// file llist.h
#ifndef LinearList_
#define LinearList_
#include<stdlib.h>
#include<iostream.h>
#include "abslist.h"
#include"xcept.h"

template<class T>
class LinearList : AbstractList<T> {
   public:
      LinearList(int MaxListSize = 10); // constructor
      ~LinearList() {delete [] element;} // destructor
      bool IsEmpty() const {return length == 0;}
      int Length() const {return length;}
      bool Find(int k, T& x) const;
         // return the k'th element of list in variable x
      int Search(const T& x) const; // return position of x
      AbstractList<T>& Delete(int k, T& x);
         // delete k'th element of list and return in x
      AbstractList<T>& Insert(int k, const T& x);
         // insert x just after k'th element
      void Output(ostream& out) const;
   private:
      int length;
      int MaxSize;
      T *element; // dynamic array
};

template<class T>
LinearList<T>::LinearList(int MaxListSize)
{// Create.
   MaxSize = MaxListSize;
   element = new T[MaxSize];
   length = 0;
}

template<class T>
bool LinearList<T>::Find(int k, T& x) const
{// Find k'th element.
   if (k < 1 || k > length) return false; // no k'th
   x = element[k - 1];
   return true;
}

template<class T>
int LinearList<T>::Search(const T& x) const
{// Locate x.
   for (int i = 0; i < length; i++)
      if (element[i] == x) return ++i;
   return 0;
}

template<class T>
AbstractList<T>& LinearList<T>::Delete(int k, T& x)
{// Delete k'th element.
   if (Find(k, x)) {// move elements k+1, ..., down
      for (int i = k; i < length; i++)
         element[i-1] = element[i];
      length--;
      return *this;
      }
   else throw OutOfBounds();
}

template<class T>
AbstractList<T>& LinearList<T>::Insert(int k, const T& x)
{// Insert x after k'th element.
   if (k < 0 || k > length) throw OutOfBounds();
   if (length == MaxSize) throw NoMem();
   // move one up
   for (int i = length-1; i >= k; i--)
      element[i+1] = element[i];
   element[k] = x;
   length++;
   return *this;
}

template<class T>
void LinearList<T>::Output(ostream& out) const
{// Put the list into the stream out.
   for (int i = 0; i < length; i++)
      out << element[i] << "  ";
}

// overload <<
template <class T>
ostream& operator<<(ostream& out, const LinearList<T>& x)
   {x.Output(out); return out;}

#endif