题解 | #在二叉树中找到两个节点的最近公共祖先#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param root TreeNode类 
     * @param o1 int整型 
     * @param o2 int整型 
     * @return int整型
     */
    int lowestCommonAncestor(TreeNode* root, int o1, int o2) {
        // write code here
        if(root==nullptr) return -1;
        if(root->val==o1||root->val==o2) return root->val;
        int a=lowestCommonAncestor(root->left, o1, o2);
        int b=lowestCommonAncestor(root->right,  o1, o2);
        if(a>=0&&b>=0) return root->val;
        else return (a==-1?b:a);
    }
};