Question

我正在使用哈希表编程实验室。我们给出的代码通过重新键入密钥（通过添加一个）来处理冲突，然后再次尝试，简单，但适用于实验室。问题是，使用原始代码，如果将成员添加到完整表，它可能会进入无限循环。我们的任务是防止这种情况发生。我使用了内容计数（contentCount），所以它不会陷入循环，即如果count> gt = = size，它就不会插入。标题和源文件位于下方。

hashTable.h

#pragma once
#include <iostream>


using namespace std;

const int NONE = 0;
const int EMPTY = -1;
const int DELETED = -2;

class HashTable
{
public:
   // Constructors
   HashTable(int size);
   HashTable(const HashTable & ht);
   ~HashTable();

   // Methods
   bool Insert(int key, int value);
   bool Search(int key, int &value);
   bool Delete(int key);
   void Print();

private:
   // Private methods
   int Hash(int key);
   int Hash2(int index);

   // Private data
   int Size;
   int *Value;
   int *Key;
   int contentCount;
};

hashTable.cpp

#include "hashTable.h"


HashTable::HashTable(int size)
{
   Size = size;
   Value = new int[Size];
   Key = new int[Size];

   for (int index=0; index < Size; index++)
   {
      Value[index] = NONE;
      Key[index] = EMPTY;
   }
}


HashTable::HashTable(const HashTable & ht)
{
    contentCount = 0;
   Size = ht.Size;
   Value = new int[Size];
   Key = new int[Size];

   for (int index=0; index < Size; index++)
   {
      Value[index] = ht.Value[index];
      Key[index] = ht.Key[index];
   }
}


HashTable::~HashTable()
{
   delete []Value;
   delete []Key;
}


bool HashTable::Insert(int key, int value)
{
    if(contentCount >= Size)
    {
        return false;
    }
   // Find desired key
   int index = Hash(key);
   while ((Key[index] != key) && (Key[index] != EMPTY))
      index = Hash2(index); 

   // Insert value into hash table
   Value[index] = value;
   Key[index] = key;
   contentCount++;
   return true;
}


bool HashTable::Search(int key, int &value)
{
   // Find desired key
   int index = Hash(key);
   while ((Key[index] != key) && (Key[index] != EMPTY))
      index = Hash2(index); 

   // Return value from hash table
   if (Key[index] == key)
      value = Value[index];
   return (Key[index] == key);
}


bool HashTable::Delete(int key)
{
   // Find desired key
   int index = Hash(key);
   while ((Key[index] != key) && (Key[index] != EMPTY))
      index = Hash2(index); 

   // Delete value from hash table
   if (Key[index] == key)
   {
      Value[index] = NONE;
      Key[index] = DELETED;
      contentCount--;
      return true;
   }
   return false;
}


int HashTable::Hash(int key)
{
   return key % Size;
}


int HashTable::Hash2(int index)
{
    cout << "COLLISION\n";
   return (index+1) % Size;
}


void HashTable::Print()
{
   cout << "Index\t" << "Value\t" << "Key\n";
   for (int index=0; index < Size; index++)
      cout << index << "\t"
           << Value[index] << "\t" 
           << Key[index] << "\n";
}

感谢您的帮助！

Answer 1

您正在复制构造函数中初始化contentCount，但在HashTable(int size)中，您不是。

很明显，它将是未初始化的。

是什么原因导致初始化的类成员变量在方法调用中变为（或显示）未初始化？

1 个答案: