Leet Code - Binary Tree Right Side View

<문제>

<답안>

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number[]}
 */
var rightSideView = function(root) {
    if (!root) return [];
    
    let array = [];
    let rightArray = [];
    search(root, 1);
    
    function search(root, level) {
        if (root) {
            if (array.length < level) {
                array.push(root.val);
            }
            search(root.right, level+1);
            search(root.left, level+1);
        } else {
            return ;
        }
    }
    return array;
    
};