【hot100-java】二叉树中的最大路径和
二叉树篇
easy.
/**
* Definition for a binary tree node.
* public 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 {
private int ret=Integer.MIN_VALUE;
public int maxPathSum(TreeNode root) {
dfs(root);
return ret;
}
private int dfs(TreeNode node){
if(node==null){
return 0;
}
int lVal=dfs(node.left);
int rVal=dfs(node.right);
ret=Math.max(ret,lVal+rVal+node.val);
return Math.max(Math.max(lVal,rVal)+node.val,0);
}
}