236. 二叉树的最近公共祖先

class Solution {
public:
    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
        //思路：求p的所有祖先，求q的所有祖先，第i个不同值为最近祖先
        TreeNode* ans;


        vector pa,qa;
        pa = ComputeAncestor (root,p);
        qa = ComputeAncestor (root,q);
        for(int i=0;i ComputeAncestor(TreeNode* root,TreeNode* x){
            vector ans;

            stack S;
            TreeNode* p=root;
            TreeNode* r=NULL;
            while(p || !S.empty() ){
                if(p){
                    S.push(p);
                    p=p->left;
                }
                else{
                    p=S.top();
                    if( !p->right || r==p->right) {
                        
                        if(x==p) {
                            int n =S.size();
                            for(int i=0;iright;





                }




            }
            return ans;





    }
};