Bloomberg 05102012 [2]

最新推荐文章于 2021-11-11 02:52:09 发布

原创最新推荐文章于 2021-11-11 02:52:09 发布 · 425 阅读

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CC 4.0 BY-SA版权

文章标签：

#arrays #apple #class

本文介绍了一种算法，用于在两个不同大小的数组中找到公共元素，并使用哈希表来实现高效的查找过程。

/*
Q: How would you find the Common elements from 2 Arrays which my or may not be of the same size?
*/


#include <iostream>
#include <string>
#include <vector>


class HashNode
{
public:
	HashNode();
	const char* key;
	int value;
};


HashNode::HashNode()
{
	key = "";
	value = 0;
};

class HashTable
{
public:
	HashTable();
	int get(const char*);
	void put(const char*);

private:
	static const int size = 2023;
	static const unsigned int seed = 131;
	HashNode nodes[size];
};


HashTable::HashTable()
{
	for(int i = 0; i < size; i++)
	{
		nodes[i] = HashNode();
	}
};

int HashTable::get(const char* key)
{
	unsigned int hash = 0;

	for(int i = 0 ; i < strlen(key); i++)
	{
		hash = hash * seed + key[i];
	}
	hash %= size;
	return nodes[hash].value;
};

void HashTable::put(const char* key)
{
	unsigned int hash = 0;
	for(int i = 0; i < strlen(key); i++)
	{
		hash = hash * seed + key[i];
	}
	hash %= size;
	nodes[hash].value++;
};



int main()
{
	std::vector<char*> v1;
	v1.push_back("apple");
	v1.push_back("babana");
	v1.push_back("citi");
	v1.push_back("oregon");
	v1.push_back("cincinnati");
	v1.push_back("oklahoma");

	std::vector<char *> v2;
	v2.push_back("cincinnati");
	v2.push_back("olabama");
	v2.push_back("apple");
	v2.push_back("nyc");

	HashTable* ht = new HashTable();

	for(std::size_t i = 0; i < v1.size(); i++)
	{
		ht->put(v1[i]);
	}

	for(std::size_t i = 0; i < v2.size(); i++)
	{
		int v = ht->get(v2[i]);
		if(v != 0)
		{
			printf("%s\n", v2[i]);
		}
	}

	return 0;
}