LeetCode——1161. 最大层内元素和

题目：1161. 最大层内元素和 - 力扣（LeetCode）

package j2;

import java.util.*;

//Definition for a binary tree node.
class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode() {
    }

    TreeNode(int val) {
        this.val = val;
    }

    TreeNode(int val, TreeNode left, TreeNode right) {
        this.val = val;
        this.left = left;
        this.right = right;
    }
}


class Solution {
    public int maxLevelSum(TreeNode root) {
        Queue<TreeNode> queue = new LinkedList<TreeNode>();
        queue.add(root);

        int max = Integer.MIN_VALUE;
        int level = 1;
        int answer = 1;

        while (!queue.isEmpty()) {
            int size = queue.size();
            int sum = 0;
            for (int i = 0; i < size; i++) {
                TreeNode temp = queue.poll();
                sum += temp.val;
                if (temp.left != null) {
                    queue.add(temp.left);
                }
                if (temp.right != null) {
                    queue.add(temp.right);
                }
            }
            if (sum > max) {
                max = sum;
                answer = level;
            }
            level++;
        }
        return answer;
    }
}


public class j3 {
    public static void main(String args[]) {
        TreeNode T = new TreeNode();
        T.val = 1;
        T.left = new TreeNode();
        T.right = new TreeNode();
        T.left.val = 7;
        T.right.val = 0;
        T.right.left = null;
        T.right.right = null;
        T.left.left = new TreeNode();
        T.left.right = new TreeNode();
        T.left.left.val = 7;
        T.left.right.val = -8;

        Solution S = new Solution();
        System.out.println(S.maxLevelSum(T));
    }
}