SegmentTree basics come true.

09-Segment-Tree/01-Segment-Tree-Basics/src/Main.java

@@ -0,0 +1,10 @@
+/**
+ * @Auther: lss
+ * @Date: 2019/2/26 20:54
+ * @Description:
+ */
+public class Main {
+ public static void main(String[] args) {
+
+ }
+}

09-Segment-Tree/01-Segment-Tree-Basics/src/SegmentTree.java

@@ -0,0 +1,40 @@
+/**
+ * @Auther: lss
+ * @Date: 2019/2/26 20:53
+ * @Description:
+ */
+public class SegmentTree<E> {
+
+ private E[] tree;
+ private E[] data;
+
+ public SegmentTree(E[] arr) {
+
+ data = (E[]) new Object[arr.length];
+ for (int i = 0; i < arr.length; i++)
+ data[i] = arr[i];
+
+ tree = (E[]) new Object[4 * arr.length];
+ }
+
+ public int getSize() {
+ return data.length;
+ }
+
+ public E get(int index) {
+ if (index < 0 || index >= data.length)
+ throw new IllegalArgumentException("Index in illegal");
+ return data[index];
+ }
+
+ // 返回完全二叉树的数组表示中，一个索引所表示的元素的左孩子节点的索引
+ private int leftChild(int index) {
+ return 2 * index + 1;
+ }
+
+ // 返回完全二叉树的数组表示中，一个索引所表示的元素的右孩子节点的索引
+ private int rightChild(int index) {
+ return 2 * index + 2;
+ }
+
+}