/** 用数组实现顺序存储完全二叉树,并进行前序遍历中序遍历后序遍历
* 1
* / \
* 2 3
* / \ /
* 4 5 6
*/
public class ArrayBinaryTreeDemo {public static void main(String[] args) {int[] tree = {1, 2, 3, 4, 5, 6};
ArrayBinaryTree arrayBinaryTree = new ArrayBinaryTree(tree);
arrayBinaryTree.preOrder(); // 1 2 4 5 3 6
arrayBinaryTree.infixOrder(); // 4 2 5 1 6 3
arrayBinaryTree.postOrder(); // 4 5 2 6 3 1}
}
class ArrayBinaryTree {private int[] arr;
public ArrayBinaryTree(int[] arr) {this.arr = arr;}
/**
* 先序遍历
*/
public void preOrder() {if (arr == null || arr.length == 0) {System.out.println("树为空!");
return;
}
preOrder(0);
System.out.println();}
/**
* 中序遍历
*/
public void infixOrder() {if (arr == null || arr.length == 0) {System.out.println("树为空!");
return;
}
infixOrder(0);
System.out.println();}
/**
* 后序遍历
*/
public void postOrder() {if (arr == null || arr.length == 0) {System.out.println("树为空!");
return;
}
postOrder(0);
System.out.println();}
private void infixOrder(int index) {
int left = index * 2 + 1; // 左子节点 index
if (left < arr.length) infixOrder(left);
System.out.print(arr[index] + " ");
int right = index * 2 + 2; // 右子节点 index
if (right < arr.length) infixOrder(right);
}
private void postOrder(int index) {
int left = index * 2 + 1;
if (left < arr.length) postOrder(left);
int right = index * 2 + 2;
if (right < arr.length) postOrder(right);
System.out.print(arr[index] + " ");
}
private void preOrder(int index) {System.out.print(arr[index] + " ");
int left = index * 2 + 1;
if (left < arr.length) {preOrder(left);
}
int right = index * 2 + 2;
if (right < arr.length) {preOrder(right);
}
}
}