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package class37;
import java.util.ArrayList;
public class Code03_AddRemoveGetIndexGreat {
public static class SBTNode<V> {
public V value;
public SBTNode<V> l;
public SBTNode<V> r;
public int size;
public SBTNode(V v) {
value = v;
size = 1;
}
}
public static class SbtList<V> {
private SBTNode<V> root;
private SBTNode<V> rightRotate(SBTNode<V> cur) {
SBTNode<V> leftNode = cur.l;
cur.l = leftNode.r;
leftNode.r = cur;
leftNode.size = cur.size;
cur.size = (cur.l != null ? cur.l.size : 0) + (cur.r != null ? cur.r.size : 0) + 1;
return leftNode;
}
private SBTNode<V> leftRotate(SBTNode<V> cur) {
SBTNode<V> rightNode = cur.r;
cur.r = rightNode.l;
rightNode.l = cur;
rightNode.size = cur.size;
cur.size = (cur.l != null ? cur.l.size : 0) + (cur.r != null ? cur.r.size : 0) + 1;
return rightNode;
}
private SBTNode<V> maintain(SBTNode<V> cur) {
if (cur == null) {
return null;
}
int leftSize = cur.l != null ? cur.l.size : 0;
int leftLeftSize = cur.l != null && cur.l.l != null ? cur.l.l.size : 0;
int leftRightSize = cur.l != null && cur.l.r != null ? cur.l.r.size : 0;
int rightSize = cur.r != null ? cur.r.size : 0;
int rightLeftSize = cur.r != null && cur.r.l != null ? cur.r.l.size : 0;
int rightRightSize = cur.r != null && cur.r.r != null ? cur.r.r.size : 0;
if (leftLeftSize > rightSize) {
cur = rightRotate(cur);
cur.r = maintain(cur.r);
cur = maintain(cur);
} else if (leftRightSize > rightSize) {
cur.l = leftRotate(cur.l);
cur = rightRotate(cur);
cur.l = maintain(cur.l);
cur.r = maintain(cur.r);
cur = maintain(cur);
} else if (rightRightSize > leftSize) {
cur = leftRotate(cur);
cur.l = maintain(cur.l);
cur = maintain(cur);
} else if (rightLeftSize > leftSize) {
cur.r = rightRotate(cur.r);
cur = leftRotate(cur);
cur.l = maintain(cur.l);
cur.r = maintain(cur.r);
cur = maintain(cur);
}
return cur;
}
private SBTNode<V> add(SBTNode<V> root, int index, SBTNode<V> cur) {
if (root == null) {
return cur;
}
root.size++;
int leftAndHeadSize = (root.l != null ? root.l.size : 0) + 1;
if (index < leftAndHeadSize) {
root.l = add(root.l, index, cur);
} else {
root.r = add(root.r, index - leftAndHeadSize, cur);
}
root = maintain(root);
return root;
}
private SBTNode<V> remove(SBTNode<V> root, int index) {
root.size--;
int rootIndex = root.l != null ? root.l.size : 0;
if (index != rootIndex) {
if (index < rootIndex) {
root.l = remove(root.l, index);
} else {
root.r = remove(root.r, index - rootIndex - 1);
}
return root;
}
if (root.l == null && root.r == null) {
return null;
}
if (root.l == null) {
return root.r;
}
if (root.r == null) {
return root.l;
}
SBTNode<V> pre = null;
SBTNode<V> suc = root.r;
suc.size--;
while (suc.l != null) {
pre = suc;
suc = suc.l;
suc.size--;
}
if (pre != null) {
pre.l = suc.r;
suc.r = root.r;
}
suc.l = root.l;
suc.size = suc.l.size + (suc.r == null ? 0 : suc.r.size) + 1;
return suc;
}
private SBTNode<V> get(SBTNode<V> root, int index) {
int leftSize = root.l != null ? root.l.size : 0;
if (index < leftSize) {
return get(root.l, index);
} else if (index == leftSize) {
return root;
} else {
return get(root.r, index - leftSize - 1);
}
}
public void add(int index, V num) {
SBTNode<V> cur = new SBTNode<V>(num);
if (root == null) {
root = cur;
} else {
if (index <= root.size) {
root = add(root, index, cur);
}
}
}
public V get(int index) {
SBTNode<V> ans = get(root, index);
return ans.value;
}
public void remove(int index) {
if (index >= 0 && size() > index) {
root = remove(root, index);
}
}
public int size() {
return root == null ? 0 : root.size;
}
}
// 通过以下这个测试,
// 可以很明显的看到LinkedList的插入、删除、get效率不如SbtList
// LinkedList需要找到index所在的位置之后才能插入或者读取时间复杂度O(N)
// SbtList是平衡搜索二叉树所以插入或者读取时间复杂度都是O(logN)
public static void main(String[] args) {
// 功能测试
int test = 50000;
int max = 1000000;
boolean pass = true;
ArrayList<Integer> list = new ArrayList<>();
SbtList<Integer> sbtList = new SbtList<>();
for (int i = 0; i < test; i++) {
if (list.size() != sbtList.size()) {
pass = false;
break;
}
if (list.size() > 1 && Math.random() < 0.5) {
int removeIndex = (int) (Math.random() * list.size());
list.remove(removeIndex);
sbtList.remove(removeIndex);
} else {
int randomIndex = (int) (Math.random() * (list.size() + 1));
int randomValue = (int) (Math.random() * (max + 1));
list.add(randomIndex, randomValue);
sbtList.add(randomIndex, randomValue);
}
}
for (int i = 0; i < list.size(); i++) {
if (!list.get(i).equals(sbtList.get(i))) {
pass = false;
break;
}
}
System.out.println("功能测试是否通过 : " + pass);
// 性能测试
test = 500000;
list = new ArrayList<>();
sbtList = new SbtList<>();
long start = 0;
long end = 0;
start = System.currentTimeMillis();
for (int i = 0; i < test; i++) {
int randomIndex = (int) (Math.random() * (list.size() + 1));
int randomValue = (int) (Math.random() * (max + 1));
list.add(randomIndex, randomValue);
}
end = System.currentTimeMillis();
System.out.println("ArrayList插入总时长(毫秒) " + (end - start));
start = System.currentTimeMillis();
for (int i = 0; i < test; i++) {
int randomIndex = (int) (Math.random() * (i + 1));
list.get(randomIndex);
}
end = System.currentTimeMillis();
System.out.println("ArrayList读取总时长(毫秒) : " + (end - start));
start = System.currentTimeMillis();
for (int i = 0; i < test; i++) {
int randomIndex = (int) (Math.random() * list.size());
list.remove(randomIndex);
}
end = System.currentTimeMillis();
System.out.println("ArrayList删除总时长(毫秒) : " + (end - start));
start = System.currentTimeMillis();
for (int i = 0; i < test; i++) {
int randomIndex = (int) (Math.random() * (sbtList.size() + 1));
int randomValue = (int) (Math.random() * (max + 1));
sbtList.add(randomIndex, randomValue);
}
end = System.currentTimeMillis();
System.out.println("SbtList插入总时长(毫秒) : " + (end - start));
start = System.currentTimeMillis();
for (int i = 0; i < test; i++) {
int randomIndex = (int) (Math.random() * (i + 1));
sbtList.get(randomIndex);
}
end = System.currentTimeMillis();
System.out.println("SbtList读取总时长(毫秒) : " + (end - start));
start = System.currentTimeMillis();
for (int i = 0; i < test; i++) {
int randomIndex = (int) (Math.random() * sbtList.size());
sbtList.remove(randomIndex);
}
end = System.currentTimeMillis();
System.out.println("SbtList删除总时长(毫秒) : " + (end - start));
}
}