GeeksforGeeks - Min distance between two given nodes of a Binary Tree - GoldmanSachs - Easy

  Node* ancestor(Node* node, int l, int m){
        if(node == NULL){
            return NULL;
        }
        if(node -> data == l or node -> data == m){
            return node;
        }
        Node* anc = ancestor(node -> left, l, m);
        Node* estor = ancestor(node -> right, l, m);
        if(anc != NULL and estor != NULL){
            return node;
        }else if(anc == NULL and estor != NULL){
            return estor;
        }
        return anc;
    }
    int dist(Node* kow, int kee){
        if(kow == NULL){
            return 0;
        }
        if(kow -> data == kee){
            return 1;
        }
        int x = dist(kow -> left, kee);
        int y = dist(kow -> right, kee);
        if(x == 0 and y == 0){
            return 0;
        }else{
            return x + y + 1;
        }
    }
    int findDist(Node* root, int a, int b) {
        Node* LCA = ancestor(root, a, b);
        int x = dist(LCA, a);
        int y = dist(LCA, b);
        return x + y - 2;
    }