题解 | #重量级的一层#

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 *   public TreeNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

public class Solution {
    /**
     * 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 root TreeNode类 
     * @return int整型
     */
    public int maxLevelSum (TreeNode root) {
        // write code here
        int maxWeight = 0;
        int result = 1;
        int level = 0;
        Queue<TreeNode> quque = new LinkedList();
        quque.add(root);
        while(!quque.isEmpty()){
            level++;
            int sum = 0;
            int size = quque.size();
            for(int i = 0;i < size;i++){
                TreeNode node = quque.poll();
                sum += node.val;

                if(node.left != null){
                    quque.add(node.left);
                }

                if(node.right != null){
                    quque.add(node.right);
                }
            }
            if(sum >= maxWeight){
                maxWeight = sum;
                result = level;
            }
        }
        return result;
    }
}