题解 | #NC102 在二叉树中找到两个节点的最近公共祖先#

类似于力扣 236.二叉树的最近公共祖先

import java.util.*;

/*
 * public class TreeNode {
 *   int val = 0;
 *   TreeNode left = null;
 *   TreeNode right = null;
 * }
 */

public class Solution {
    /**
     * 
     * @param root TreeNode类 
     * @param o1 int整型 
     * @param o2 int整型 
     * @return int整型
     */
    public int lowestCommonAncestor (TreeNode root, int o1, int o2) {
        // write code here
        if(root == null || root.val == o1 || root.val == o2) return root == null ? 0 : root.val;
        int left = lowestCommonAncestor(root.left, o1, o2);
        int right = lowestCommonAncestor(root.right, o1, o2);
        if (left == 0) return right;
        if (right == 0) return left;
        return root.val;
    }
}