思路

先推右邊再推左邊，左邊就是佇列裡的最後一個了
複製程式碼

原始碼

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var findBottomLeftValue = function(root) {
    let q = [];
    let res;
    q.push(root);
    while(q.length){
        let node = q.shift();
        res = node.val;
        if(node.right){
            q.push(node.right);
        }
        if(node.left){
            q.push(node.left);
        }
    }
    return res;
};
複製程式碼