题解 | #从上往下打印二叉树#

    this.val = x;
    this.left = null;
    this.right = null;
} */
//不明白自己为什么在广度优先卡了十分钟，需要多重复练习！
//重构二叉树的题，有时需要new TreeNode
function PrintFromTopToBottom(root)
{
    // write code here
    let res=[]
    let resp=[]
    if(root){resp.push(root)}
    else return res
    while(resp.length){
        let p=resp[0]
        resp.splice(0,1)
        res.push(p.val)
        if(p.left){resp.push(p.left)}
        if(p.right){resp.push(p.right)}
    }
    return res
}
module.exports = {
    PrintFromTopToBottom : PrintFromTopToBottom
};