Java创建二叉树

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https://blog.csdn.net/yeweiouyang/article/details/37814461

二叉树的值保存在数组中，以0作为分隔，数字0表示空节点，数组

public static final int[] TREE_VALUE = new int[]{1,2,3,0,4,5,0,0,6,0,0,7,0,0,8,0,9,10,0,0,0};

表示的二叉树是：

/**
 * 维护构建二叉树的值和值索引
 */
public static class TreeValue {
	public static int index = 0;
	public static final int[] TREE_VALUE = new int[]{1,2,3,0,4,5,0,0,6,0,0,7,0,0,8,0,9,10,0,0,0};
}

/**
 * Create A Binary Tree with TreeValue
 * 
 * @node: a tree node
 * @i: the index of tree value
 */
public static TreeNode createTree(TreeNode node, int i) {
	if (0 == TreeValue.TREE_VALUE[i]) {
		return null;
	} else {
		node.setVal(TreeValue.TREE_VALUE[i]);
	}
	
	TreeNode leftChild = new TreeNode();
	node.left = createTree(leftChild, ++TreeValue.index);
	TreeNode rightChild = new TreeNode();
	node.right = createTree(rightChild, ++TreeValue.index);

	return node;
}

/**
 * Definition for binary tree
 */
public static class TreeNode {
	int val;
	TreeNode left;
	TreeNode right;
	
	TreeNode() {
		left = null;
		right = null;
	}
	TreeNode(int val) {
		this.val = val;
		left = null;
		right = null;
	}
	
	public void setVal(int val) {
		this.val = val;
	}
}

public static void main(String[] args) {
	TreeNode root = new TreeNode();
	root = createTree(root, index);
}