顺序储存二叉树

顺序储存二叉树的遍历

public class ArrBinaryTreeDemo {
    public static void main(String[] args) {
        int[] arr={1,2,3,4,5,6,7};
        ArrBinaryTree abt=new ArrBinaryTree(arr);
        abt.preOrder();
        System.out.println("-----------------------------------");
        abt.infixOrder();
        System.out.println("-----------------------------------");
        abt.postOrder();

    }

}
class ArrBinaryTree{
    private int[] arr;

    public ArrBinaryTree(int[] arr) {
        this.arr = arr;
    }
    public void preOrder(){
        this.preOrder(0);
    }

    //前序遍历
    public void preOrder(int index){
        if(arr==null||arr.length==0)
        {
            System.out.println("数组为空");
            return;
        }
        System.out.println(arr[index]);
        if((index*2+1)<arr.length)
            preOrder(2*index+1);
        if((index*2+2)<arr.length)
            preOrder(2*index+2);
    }

    public void infixOrder(){
        this.infixOrder(0);
    }
    //中序遍历
    public void infixOrder(int index){
        if(arr==null||arr.length==0)
        {
            System.out.println("数组为空");
            return;
        }
        if((index*2+1)<arr.length)
            infixOrder(2*index+1);

        System.out.println(arr[index]);

        if((index*2+2)<arr.length)
            infixOrder(2*index+2);
    }

    public void postOrder(){
        this.postOrder(0);
    }
    //后序遍历
    public void postOrder(int index){
        if(arr==null||arr.length==0)
        {
            System.out.println("数组为空");
            return;
        }
        if((index*2+1)<arr.length)
            postOrder(2*index+1);
        if((index*2+2)<arr.length)
            postOrder(2*index+2);
        System.out.println(arr[index]);
    }
}