Lowest Common Ancestor in a BST

Given a Binary Search Tree (with all values unique) and two node values. Find the Lowest Common Ancestors of the two nodes in the BST.

• Time : O(d)
• Space : O(d)

bool inRange(int mi, int ma, int target) {
    return mi < target and target < ma;
}

pair<bool, Node*> helper(Node* node, int v1, int v2, int mi, int ma) {
    if(!node) return{false, nullptr};
    if(!(inRange(mi, ma, v1) or inRange(mi, ma, v2))) return {false, nullptr};
    
    
    if(node->data == v1) {
        auto rp = helper(node->right, v1, v2, v1, ma);
        if(rp.first) return {true, node};
        return {true, nullptr};
    } else if(node->data == v2) {
        auto lp = helper(node->left, v1, v2, mi, v2);
        if(lp.first) return {true, node};
        return {true, nullptr};
    }
    if(inRange(mi, ma, v1) or inRange(mi, ma, v2)) {
        auto lp = helper(node->left, v1, v2, mi, node->data);
        if(lp.second) return lp;
        auto rp = helper(node->right, v1, v2, node->data, ma);
        if(rp.second) return rp;
        if(lp.first && rp.first) return {true, node};
        if(lp.first) return lp;
        if(rp.first) return rp;
        return {false, nullptr};   
    } else if(inRange(mi, ma, v1)) {
        return helper(node->left, v1, v2, mi, node->data);
    } else {
        return helper(node->right, v1, v2, node->data, ma);
    }
}
Node* LCA(Node *root, int n1, int n2) {
   return helper(root, min(n1,n2), max(n1,n2), INT_MIN, INT_MAX).second;
}