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package hashset.train;
import java.util.HashSet;
//import java.util.Random;
import java.util.Set;
public class HashSetDemo {
public static void main(String[] args) {
Set<Integer> hs =new HashSet<Integer>();
// Random rand=new Random();
hs.add(6);
hs.add(100);
hs.add(150);
hs.add(240);
hs.add(330);
hs.add(520); // 乱序 在table中位置是根据hash算法计算得出的 但只是会影响存储位置 不是一定会使元素变得自然排序(像依次添加那样 估计与table的长度的增加有关) 但是若用随机数添加又符合规律?
// for (int i=0;i<5000;i++){
// hs.add(rand.nextInt(1000));
// }
// for (int i=0;i<1000;i++) {
// System.out.println(i);
// }
for (int i : hs) {
System.out.println(i);
}
}
}
final V putVal(int hash, K key, V value, boolean onlyIfAbsent,
boolean evict) {
Node<K,V>[] tab; Node<K,V> p; int n, i;
if ((tab = table) == null || (n = tab.length) == 0)
n = (tab = resize()).length;
if ((p = tab[i = (n - 1) & hash]) == null)
tab[i] = newNode(hash, key, value, null);
else {
Node<K,V> e; K k;
if (p.hash == hash &&
((k = p.key) == key || (key != null && key.equals(k))))
e = p;
else if (p instanceof TreeNode)
e = ((TreeNode<K,V>)p).putTreeVal(this, tab, hash, key, value);
else {
for (int binCount = 0; ; ++binCount) {
if ((e = p.next) == null) {
p.next = newNode(hash, key, value, null);
if (binCount >= TREEIFY_THRESHOLD - 1) // -1 for 1st
treeifyBin(tab, hash);
break;
}
if (e.hash == hash &&
((k = e.key) == key || (key != null && key.equals(k))))
break;
p = e;
}
}
if (e != null) { // existing mapping for key
V oldValue = e.value;
if (!onlyIfAbsent || oldValue == null)
e.value = value;
afterNodeAccess(e);
return oldValue;
}
}
++modCount;
if (++size > threshold)
resize();
afterNodeInsertion(evict);
return null;
}
static final int tableSizeFor(int cap) {
int n = cap - 1;
n |= n >>> 1;
n |= n >>> 2;
n |= n >>> 4;
n |= n >>> 8;
n |= n >>> 16;
return (n < 0) ? 1 : (n >= MAXIMUM_CAPACITY) ? MAXIMUM_CAPACITY : n + 1;
}
if (++size > threshold)
resize();
final V putVal(int hash, K key, V value, boolean onlyIfAbsent,
boolean evict) {
Node<K,V>[] tab; Node<K,V> p; int n, i;
if ((tab = table) == null || (n = tab.length) == 0)
n = (tab = resize()).length;
if ((p = tab[i = (n - 1) & hash]) == null)
tab[i] = newNode(hash, key, value, null);
else {
Node<K,V> e; K k;
if (p.hash == hash &&
((k = p.key) == key || (key != null && key.equals(k))))
e = p;
else if (p instanceof TreeNode)
e = ((TreeNode<K,V>)p).putTreeVal(this, tab, hash, key, value);
else {
for (int binCount = 0; ; ++binCount) {
if ((e = p.next) == null) {
p.next = newNode(hash, key, value, null);
if (binCount >= TREEIFY_THRESHOLD - 1) // -1 for 1st
treeifyBin(tab, hash);
break;
}
if (e.hash == hash &&
((k = e.key) == key || (key != null && key.equals(k))))
break;
p = e;
}
}
if (e != null) { // existing mapping for key
V oldValue = e.value;
if (!onlyIfAbsent || oldValue == null)
e.value = value;
afterNodeAccess(e);
return oldValue;
}
}
++modCount;
if (++size > threshold)
resize();
afterNodeInsertion(evict);
return null;
}
[/quote]
if (++size > threshold)
resize();
HashSet<Integer> hs = new HashSet<Integer>(4);
hs.add(3);
hs.add(9);
hs.add(1);
hs.add(2);
HashSet<Integer> hs = new HashSet<Integer>(4);
hs.add(3);
hs.add(1);
hs.add(9);
hs.add(2);
HashSet<Integer> hs = new HashSet<Integer>(4);
hs.add(3);
hs.add(5);
HashSet<Integer> hs = new HashSet<Integer>(4);
hs.add(3);
hs.add(5);
hs.add(1);
hs.add(2);