数据结构之 哈希表

头文件：HashTable.h

#define _INT_MIN (0x80000000)
class HashTable
{
public:
HashTable(int hashLen);
HashTable(int ary[], int n, int hashLen);
HashTable(int *start,int *end,int hashLen);
//获取哈希码
int HashCode(int key, int *cPtr );
//冲突处理
int Collision(int H, int key, int *cPtr );
//初始化哈希表
void Initial(int hashLen);

int ToArray(int ary[]);

int AddRange(int ary[], int n);

int Add(int key);
private:
CirSeqList csl;
int len;

int SqrtSearchHashes(int H, int key, int *cPtr );
};

void HashTable::Initial(int hashLen)
{
len = hashLen;
//初始化 循环表
int *a = new int[hashLen];
for (int i = 0; i < hashLen; i++)
{
//int的最小值
a[i] = _INT_MIN;
}
csl.Initial(a, hashLen);
delete[] a;
}

HashTable::HashTable(int hashLen)
{
Initial(hashLen);
}

HashTable::HashTable(int ary[], int n, int hashLen)
{
Initial(hashLen);
AddRange(ary, n);
}

HashTable::HashTable(int *start, int *end, int hashLen)
{
Initial(hashLen);
AddRange(start, end - start + 1);
}

int HashTable::Add(int key)
{
int count = 0, H = HashCode(key, &count);
if (H != -1)
{
csl.Set(H, key);
}
else
{
//printf("\n*****哈希表溢出！*****\n");
}
return count;
}

int HashTable::AddRange(int ary[], int n)
{
int count = 0;
for (int i = 0; i < n; i++)
{
count+=Add(ary[i]);
}
return count;
}

//获取哈希码
int HashTable::HashCode(int key, int *cPtr = NULL)
{
int H = key%7, count = 1;

//如果是的，就直接返回。防止重复元素出现。
if (csl.Get(H) == key)
{
return H;
}
else if (csl.Get(H) != _INT_MIN)
{
//寻找空位
H = Collision(H, _INT_MIN, &count);
if (H == -1)
{
//printf("\n*****哈希表溢出！*****\n");
return -1;
}
}
(*cPtr) = count;
return H;

}
//冲突处理
int HashTable::Collision(int H, int key, int *cPtr = NULL)
{
bool noway=false;
int method = 0, tar = -1;

//遍历处理冲突的方法表
while (noway == false && method++, tar == -1)
{
switch (method)
{
case 1:
//方法一：二次探测再散列
tar = SqrtSearchHashes(H, key, cPtr);
break;
case 2:
//方法二：。。。。。。
tar = -1;
break;
default:
//方法表已穷尽
noway = true;
break;
}
}

return tar;
}

//1^2 2^2 3^3
int HashTable::SqrtSearchHashes(int H, int key = _INT_MIN, int *cPtr = NULL)
{
int i = 1, tar = H, d;
while (csl.IsLegal(tar) && csl.Get(tar) != key)
{
if (i > len / 2)
{
return -1;
}
d = i * i;
tar = (H + d) % len;
if (cPtr != NULL)
{
(*cPtr)++;
}
i++;
}
return tar;
}

int HashTable::ToArray(int ary[])
{
csl.SetCurNum(len-1);
for (int i = 0; i < len; i++)
{
ary[i] = csl.Next();
}
return len;
}