题解 | #将升序数组转化为平衡二叉搜索树#

/*
 * function TreeNode(x) {
 *   this.val = x;
 *   this.left = null;
 *   this.right = null;
 * }
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 *
 * @param nums int整型一维数组
 * @return TreeNode类
 */
class Tnode {
    constructor() {
        this.root = null;
    }
    intNode(value) {
        let newNode = new TreeNode(value);
        if (this.root === null) {
            this.root = newNode;
        } else {
            if (this.root.val > newNode.val) {
                this.insertNodeLeft(this.root,newNode);
            } else if(this.root.val < newNode.val){
                this.insertNodeRight(this.root,newNode)
            }
        }
    }
    insertNodeLeft(node, newNode) {
        if (node.left === null) {
            node.left = newNode;
        } else {
            this.insertNodeLeft(node.left, newNode);
        }
    }
    insertNodeRight(node, newNode) {
        if (node.right === null) {
            node.right = newNode;
        } else {
            this.insertNodeRight(node.right, newNode);
        }
    }
}
function sortedArrayToBST(nums) {
    // write code here
    let arr = nums.sort();
    let nnnode = new Tnode();
    nnnode.intNode(arr[arr.length/2]);
    let arr2 = []
    let arr3 = []
    for (let i = 0; i < arr.length; i++) {
        if(i<arr.length/2){
            arr2.push(arr[i])
        }else{
            arr3.push(arr[i])
        }
    }
    for (let i = arr2.length - 1; i >= 0; i--) {
        nnnode.intNode(arr2[i]);
    }
    for (let i = 0; i <arr3.length; i++) {
        nnnode.intNode(arr3[i]);
    }
    return nnnode.root;
}
module.exports = {
    sortedArrayToBST: sortedArrayToBST,
};