java開放地址法和鏈地址法解決hash沖突的方法示例

public class Info {
	private String key;			//關(guān)鍵字，或者能標(biāo)識對象的唯一屬性
	private String name;		//值域
	
	public Info(String key, String name) {
		this.key = key;
		this.name = name;
	}

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
}

/**
 * 模擬hashMap
 *
 */
public class HashTable {
	
	private Info[] arr;
	
	/**
	 * 默認(rèn)的構(gòu)造方法
	 */
	public HashTable() {
		arr = new Info[100];
	}
	
	/**
	 * 指定數(shù)組初始化大小
	 */
	public HashTable(int maxSize) {
		arr = new Info[maxSize];
	}
	
	/**
	 * 插入數(shù)據(jù)
	 */
	public void insert(Info info) {
		//獲得關(guān)鍵字
		String key = info.getKey();
		//關(guān)鍵字所自定的哈希數(shù)
		int hashVal = hashCode(key);
		//如果這個(gè)索引已經(jīng)被占用，而且里面是一個(gè)未被刪除的數(shù)據(jù)
		while(arr[hashVal] != null && arr[hashVal].getName() != null) {
			//進(jìn)行遞加，避免漏找
			++hashVal;
			//循環(huán)
			hashVal %= arr.length;
		}
		arr[hashVal] = info;
	}
	
	/**
	 * 查找數(shù)據(jù)
	 */
	public Info find(String key) {
		int hashVal = hashCode(key);
		while(arr[hashVal] != null) {
			if(arr[hashVal].getKey().equals(key)) {
				return arr[hashVal];
			}
			++hashVal;
			hashVal %= arr.length;
		}
		return null;
	}
	
	/**
	 * 刪除數(shù)據(jù)
	 */
	public Info delete(String key) {
		int hashVal = hashCode(key);
		//循環(huán)查找，數(shù)組中下標(biāo)為hashVal的值，沒有找到返回null
		while(arr[hashVal] != null) {
			if(arr[hashVal].getKey().equals(key)) {
				Info tmp = arr[hashVal];
				tmp.setName(null);
				return tmp;
			}
			++hashVal;			//由于數(shù)組的值是連續(xù)的，為了避免漏找，需要依次往下找
			hashVal %= arr.length;
		}
		return null;
	}
	
	/**
	 * 獲得關(guān)鍵字的hash值，也可以自定義
	 */
	public int hashCode(String key) {
		
		BigInteger hashVal = new BigInteger("0");
		BigInteger pow27 = new BigInteger("1");
		for(int i = key.length() - 1; i >= 0; i--) {
			int letter = key.charAt(i) - 96;
			BigInteger letterB = new BigInteger(String.valueOf(letter));
			hashVal = hashVal.add(letterB.multiply(pow27));
			pow27 = pow27.multiply(new BigInteger(String.valueOf(27)));
		}
		return hashVal.mod(new BigInteger(String.valueOf(arr.length))).intValue();
	}
}

public class Info {
	
	private String key;
	private String name;
	
	public Info(String key, String name) {
		this.key = key;
		this.name = name;
	}

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}
	
	
	
}

public class Node {

	// 數(shù)據(jù)域
	public Info info;
	// 指針域,指向?qū)ο乱粋€(gè)節(jié)點(diǎn)引用
	public Node next;

	public Node(Info info) {
		this.info = info;
	}

}

/**
 * 模擬linkedList
 * 
 * @author asus
 *
 */
public class LinkList {

	// 頭結(jié)點(diǎn)
	private Node first;

	public LinkList() {
		first = null;
	}

	// 插入一個(gè)節(jié)點(diǎn)
	public void insertFirst(Info info) {
		Node node = new Node(info);
		node.next = first;
		first = node;
	}

	// 刪除一個(gè)節(jié)點(diǎn)，在頭結(jié)點(diǎn)后進(jìn)行刪除
	public Node deleteFirst() {
		Node temp = first;
		first = temp.next;
		return temp;
	}

	/**
	 * 查找方法
	 */
	public Node find(String key) {
		Node current = first;
		while (!key.equals(current.info.getKey())) {
			if (current.next == null) {
				return null;
			}
			current = current.next;
		}
		return current;
	}

	/**
	 * 刪除方法
	 */
	public Node delete(String key) {
		Node current = first;
		Node previous = first;
		while (!key.equals(current.info.getKey())) {
			if (current.next == null) {
				return null;
			}
			previous = current;
			current = current.next;
		}

		if (current == first) {
			first = first.next;
		} else {
			previous.next = current.next;
		}
		return current;

	}

}

public class HashTable {

	private LinkList[] arr;

	/**
	 * 默認(rèn)的構(gòu)造方法
	 */
	public HashTable() {
		arr = new LinkList[100];
	}

	/**
	 * 指定數(shù)組初始化大小
	 */
	public HashTable(int maxSize) {
		arr = new LinkList[maxSize];
	}

	/**
	 * 插入數(shù)據(jù)
	 */
	public void insert(Info info) {
		String key = info.getKey();
		// 獲取關(guān)鍵字的自定義hash函數(shù)
		int hashVal = hashCode(key);

		if (arr[hashVal] == null) {		//如果數(shù)組某個(gè)單元的位置為空，則需要重新構(gòu)造一個(gè)linkList
			arr[hashVal] = new LinkList();
		}
		arr[hashVal].insertFirst(info);
	}

	/**
	 * 查找數(shù)據(jù)
	 */
	public Info find(String key) {
		int hashVal = hashCode(key);
		return arr[hashVal].find(key).info;
	}
	
	/**
	 * 刪除數(shù)據(jù)
	 */
	public Info delete(String key){
		int hashVal = hashCode(key);
		return arr[hashVal].delete(key).info;
	}
	

	/**
	 * 自定義計(jì)算hash的函數(shù)
	 */
	public int hashCode(String key) {

		BigInteger hashVal = new BigInteger("0");
		BigInteger pow27 = new BigInteger("1");
		for (int i = key.length() - 1; i >= 0; i--) {
			int letter = key.charAt(i) - 96;
			BigInteger letterB = new BigInteger(String.valueOf(letter));
			hashVal = hashVal.add(letterB.multiply(pow27));
			pow27 = pow27.multiply(new BigInteger(String.valueOf(27)));
		}
		return hashVal.mod(new BigInteger(String.valueOf(arr.length))).intValue();
	}

}