解决散列表冲突的第一种方法通常叫做分离连接法，其做法是将散列到同一个值得所有元素保留到一个表中。我们可以使用标准库的实现方法。如果空间很紧，则更可取的方法是避免使用它们（因为这些表是双向链接的并且浪费空间） 下面给出一个例子： package hash;
import java.util.LinkedList; import java.util.List; import java.util.Iterator; import java.util.Random;
public class SeprateChainingHashTable<AnyType> { private static final int DEFAULT_TABLE_SIZE=10;//默认容量 private List<AnyType>[] theLists;//散列表的数组 private int currentSize;//当前数据个数 public SeprateChainingHashTable(){ this(DEFAULT_TABLE_SIZE); } public SeprateChainingHashTable(int size) { // TODO Auto-generated constructor stub theLists = new LinkedList[nextPrime(size)]; for (int i = 0; i < theLists.length; i++) { theLists[i] = new LinkedList<AnyType>(); } } public void makeEmpty() { for(List<AnyType>list:theLists){ list.clear(); } currentSize=0; } public boolean contains(AnyType x){ List<AnyType> whichList =theLists[myhash(x)]; return whichList.contains(x); } public void insert(AnyType x) { List<AnyType> whichList = theLists[myhash(x)]; if (!whichList.contains(x)) { whichList.add(x); if (++currentSize > theLists.length) { rehash(); } } else { } } public void remove(AnyType x){ List<AnyType> whichList = theLists[myhash(x)]; if(whichList.contains(x)){ whichList.remove(x); currentSize--; }else{
}
}
private int myhash(AnyType x) {
// TODO Auto-generated method stub
int hashVal=x.hashCode();
hashVal%=theLists.length;
if(hashVal<0){
hashVal+=theLists.length;
}
return hashVal;
}
private void rehash() {
// TODO Auto-generated method stub
List<AnyType>[] oldLists=theLists;
theLists=new List[nextPrime(2*theLists.length)];
for(int j=0;j<theLists.length;j++){
theLists[j]=new LinkedList<AnyType>();
}
currentSize =0;
for(int i=0;i<oldLists.length;i++){
for(AnyType item:oldLists[i]){
insert(item);
}
}
}
private static boolean isPrime(int num){
if(num==2||num==3){
return true;
}
if(num==1||num%2==0){
return false;
}
for(int i=3;i*i<=num;i+=2){
if(num%i==0){
return false;
}
}
return true;
}
private int nextPrime(int num) {
// TODO Auto-generated method stub
if(num==0||num==1||num==2){
return 2;
}
if(num%2==0){
num++;
}
while (!isPrime(num)) {
num+=2;
}
return num;
}
public void printTable(){
for(int i=0;i<theLists.length;i++){
System.out.println("---------");
Iterator iterator=theLists[i].iterator();
while(iterator.hasNext()){
System.out.print(iterator.next()+"");
}
System.out.println();
}
}
public static void main(String[] args){
Random random=new Random();
SeprateChainingHashTable<Integer> hashTable=new SeprateChainingHashTable<Integer>();
for(int i=0;i<30;i++){
hashTable.insert(random.nextInt(30));
}
hashTable.printTable();
}
}
