lowest-common-ancestor.cpp

#include <bits/stdc++.h>
using namespace std;

class Node {
    public:
        int data;
        Node *left;
        Node *right;
        Node(int d) {
            data = d;
            left = NULL;
            right = NULL;
        }
};

class Solution {
    public:
  		Node* insert(Node* root, int data) {
            if(root == NULL) {
                return new Node(data);
            } else {
                Node* cur;
                if(data <= root->data) {
                    cur = insert(root->left, data);
                    root->left = cur;
                } else {
                    cur = insert(root->right, data);
                    root->right = cur;
               }

               return root;
           }
        }
      Node *lca(Node *root, int v1,int v2)
      {
        if(root->data>v1 && root->data>v2)
            return lca(root->left,v1,v2);
        if(root->data<v1 && root->data<v2)
            return lca(root->right,v1,v2);
        return root;
    }
};
int main() {
  
    Solution myTree;
    Node* root = NULL;
    
    int t;
    int data;

    std::cin >> t;

    while(t-- > 0) {
        std::cin >> data;
        root = myTree.insert(root, data);
    }
  	
  	int v1, v2;
  	std::cin >> v1 >> v2;
  
    Node *ans = myTree.lca(root, v1, v2);
    
  	std::cout << ans->data;

    return 0;
}