代码如下:

#include <iostream>
#include <vector>
using namespace std;template<typename K>
struct HashNode
{typedef HashNode<K> Node;K _val;Node * _next;HashNode(const K & val):_val(val),_next(nullptr){}
};template<typename K>
class HashTable
{
public:typedef HashNode<K> Node;HashTable(int n = 10):_ht(10),_size(0){}bool insert(const K & val){checkCapacity();int idx = val % _ht.size();Node *cur = _ht[idx];while (cur){if (cur->_val == val) return false;cur = cur->_next;}cur = new Node(val);cur->_next = _ht[idx];_ht[idx] = cur;++_size;return true;}void checkCapacity(){if (_size == _ht.size()){int newC = _size == 0 ? 10 : 2 * _size;vector<Node *> newHt(newC);for (size_t i = 0; i < _ht.size(); i++){Node *cur = _ht[i];while (cur){Node *next = cur->_next;int idx = cur->_val % newHt.size();cur->_next = newHt[idx];newHt[idx] = cur;cur = next;}_ht[i] = nullptr;}swap(_ht, newHt);}}Node *find(const K & val){int idx = val % _ht.size();Node *cur = _ht[idx];while (cur){if (cur->_val == val) return cur;cur = cur->_next;}return nullptr;}bool erase(const K & val){Node *node = find(val);if (node){int idx = val % _ht.size();Node *cur = _ht[idx];Node *prev = nullptr;while (cur != node){prev = cur;cur = cur->_next;}Node *next = cur->_next;if (prev) prev->_next = next;else _ht[idx] = next;--_size;delete node;return true;}return false;}private:vector<Node *> _ht;int _size;
};int main()
{HashTable<int> h;h.insert(12321);h.insert(131);h.insert(123);cout << h.find(131)->_val << endl;return 0;
}

测试结果: