package class37; import java.util.ArrayList; import java.util.Arrays; import java.util.Comparator; import java.util.LinkedList; public class Problem_0406_QueueReconstructionByHeight { public static int[][] reconstructQueue1(int[][] people) { int N = people.length; Unit[] units = new Unit[N]; for (int i = 0; i < N; i++) { units[i] = new Unit(people[i][0], people[i][1]); } Arrays.sort(units, new UnitComparator()); ArrayList arrList = new ArrayList<>(); for (Unit unit : units) { arrList.add(unit.k, unit); } int[][] ans = new int[N][2]; int index = 0; for (Unit unit : arrList) { ans[index][0] = unit.h; ans[index++][1] = unit.k; } return ans; } public static int[][] reconstructQueue2(int[][] people) { int N = people.length; Unit[] units = new Unit[N]; for (int i = 0; i < N; i++) { units[i] = new Unit(people[i][0], people[i][1]); } Arrays.sort(units, new UnitComparator()); SBTree tree = new SBTree(); for (int i = 0; i < N; i++) { tree.insert(units[i].k, i); } LinkedList allIndexes = tree.allIndexes(); int[][] ans = new int[N][2]; int index = 0; for (Integer arri : allIndexes) { ans[index][0] = units[arri].h; ans[index++][1] = units[arri].k; } return ans; } public static class Unit { public int h; public int k; public Unit(int height, int greater) { h = height; k = greater; } } public static class UnitComparator implements Comparator { @Override public int compare(Unit o1, Unit o2) { return o1.h != o2.h ? (o2.h - o1.h) : (o1.k - o2.k); } } public static class SBTNode { public int value; public SBTNode l; public SBTNode r; public int size; public SBTNode(int arrIndex) { value = arrIndex; size = 1; } } public static class SBTree { private SBTNode root; private SBTNode rightRotate(SBTNode cur) { SBTNode 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 leftRotate(SBTNode cur) { SBTNode 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 maintain(SBTNode 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 insert(SBTNode root, int index, SBTNode cur) { if (root == null) { return cur; } root.size++; int leftAndHeadSize = (root.l != null ? root.l.size : 0) + 1; if (index < leftAndHeadSize) { root.l = insert(root.l, index, cur); } else { root.r = insert(root.r, index - leftAndHeadSize, cur); } root = maintain(root); return root; } private SBTNode get(SBTNode 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); } } private void process(SBTNode head, LinkedList indexes) { if (head == null) { return; } process(head.l, indexes); indexes.addLast(head.value); process(head.r, indexes); } public void insert(int index, int value) { SBTNode cur = new SBTNode(value); if (root == null) { root = cur; } else { if (index <= root.size) { root = insert(root, index, cur); } } } public int get(int index) { SBTNode ans = get(root, index); return ans.value; } public LinkedList allIndexes() { LinkedList indexes = new LinkedList<>(); process(root, indexes); return indexes; } } // 通过以下这个测试, // 可以很明显的看到LinkedList的插入和get效率不如SBTree // 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) // SBTree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 = 10000; int max = 1000000; boolean pass = true; LinkedList list = new LinkedList<>(); SBTree sbtree = new SBTree(); for (int i = 0; i < test; i++) { int randomIndex = (int) (Math.random() * (i + 1)); int randomValue = (int) (Math.random() * (max + 1)); list.add(randomIndex, randomValue); sbtree.insert(randomIndex, randomValue); } for (int i = 0; i < test; i++) { if (list.get(i) != sbtree.get(i)) { pass = false; break; } } System.out.println("功能测试是否通过 : " + pass); // 性能测试 test = 50000; list = new LinkedList<>(); sbtree = new SBTree(); long start = 0; long end = 0; start = System.currentTimeMillis(); for (int i = 0; i < test; i++) { int randomIndex = (int) (Math.random() * (i + 1)); int randomValue = (int) (Math.random() * (max + 1)); list.add(randomIndex, randomValue); } end = System.currentTimeMillis(); System.out.println("LinkedList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("LinkedList读取总时长(毫秒) : " + (end - start)); start = System.currentTimeMillis(); for (int i = 0; i < test; i++) { int randomIndex = (int) (Math.random() * (i + 1)); int randomValue = (int) (Math.random() * (max + 1)); sbtree.insert(randomIndex, randomValue); } end = System.currentTimeMillis(); System.out.println("SBTree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)); sbtree.get(randomIndex); } end = System.currentTimeMillis(); System.out.println("SBTree读取总时长(毫秒) : " + (end - start)); } }