Next Node on Its Right - Google Top Interview Questions
Problem Statement :
You are given a binary tree root containing unique values, and an integer target. Find the node with value target and return the node that's directly right of it on its level. If the target node doesn't exist or if it's already in the rightmost position, return null. Constraints 0 ≤ n ≤ 100,000 where n is the number of nodes in root Example 1 Input Visualize tree = [1, [2, [4, null, null], [5, null, null]], [3, null, [6, [7, null, null], null]]] target = 5 Output [6, [7, null, null], null] Example 2 Input tree = [1, [2, null, null], [3, null, null]] target = 3 Output null Explanation There's no node directly to the right of 3. Example 3 Input tree = [1, null, null] target = 2 Output null Explanation Node 2 doesn't exist.
Solution :
Solution in C++ :
Tree* solve(Tree* tree, int target) {
if (not tree) {
return nullptr;
}
queue<Tree*> q;
q.push(tree);
Tree* cur;
while (not q.empty()) {
int s = q.size();
while (s--) {
cur = q.front();
q.pop();
if (cur->val == target) {
if (s >= 1) {
Tree* now = q.front();
q.pop();
return now;
}
}
if (cur->left) {
q.push(cur->left);
}
if (cur->right) {
q.push(cur->right);
}
}
}
return nullptr;
}
Solution in Java :
import java.util.*;
/**
* public class Tree {
* int val;
* Tree left;
* Tree right;
* }
*/
class Solution {
public Tree solve(Tree tree, int target) {
Queue<Tree> q = new LinkedList();
q.offer(tree);
boolean trigger = false;
while (!q.isEmpty()) {
int size = q.size();
for (int x = 0; x < size; x++) {
Tree temp = q.poll();
if (trigger) {
return temp;
}
if (temp.val == target) {
trigger = true;
}
if (temp.left != null)
q.offer(temp.left);
if (temp.right != null)
q.offer(temp.right);
}
if (trigger)
return null;
}
return null;
}
}
Solution in Python :
class Solution:
def solve(self, tree, target):
q = deque()
q.append(tree)
while q:
isInLevel = len(q)
while isInLevel:
temp = q.popleft()
if temp.val == target:
if isInLevel > 1:
return q.popleft()
else:
return None
if temp.left:
q.append(temp.left)
if temp.right:
q.append(temp.right)
isInLevel -= 1
return None
View More Similar Problems
Unique Colors
You are given an unrooted tree of n nodes numbered from 1 to n . Each node i has a color, ci. Let d( i , j ) be the number of different colors in the path between node i and node j. For each node i, calculate the value of sum, defined as follows: Your task is to print the value of sumi for each node 1 <= i <= n. Input Format The first line contains a single integer, n, denoti
View Solution →Fibonacci Numbers Tree
Shashank loves trees and math. He has a rooted tree, T , consisting of N nodes uniquely labeled with integers in the inclusive range [1 , N ]. The node labeled as 1 is the root node of tree , and each node in is associated with some positive integer value (all values are initially ). Let's define Fk as the Kth Fibonacci number. Shashank wants to perform 22 types of operations over his tree, T
View Solution →Pair Sums
Given an array, we define its value to be the value obtained by following these instructions: Write down all pairs of numbers from this array. Compute the product of each pair. Find the sum of all the products. For example, for a given array, for a given array [7,2 ,-1 ,2 ] Note that ( 7 , 2 ) is listed twice, one for each occurrence of 2. Given an array of integers, find the largest v
View Solution →Lazy White Falcon
White Falcon just solved the data structure problem below using heavy-light decomposition. Can you help her find a new solution that doesn't require implementing any fancy techniques? There are 2 types of query operations that can be performed on a tree: 1 u x: Assign x as the value of node u. 2 u v: Print the sum of the node values in the unique path from node u to node v. Given a tree wi
View Solution →Ticket to Ride
Simon received the board game Ticket to Ride as a birthday present. After playing it with his friends, he decides to come up with a strategy for the game. There are n cities on the map and n - 1 road plans. Each road plan consists of the following: Two cities which can be directly connected by a road. The length of the proposed road. The entire road plan is designed in such a way that if o
View Solution →Heavy Light White Falcon
Our lazy white falcon finally decided to learn heavy-light decomposition. Her teacher gave an assignment for her to practice this new technique. Please help her by solving this problem. You are given a tree with N nodes and each node's value is initially 0. The problem asks you to operate the following two types of queries: "1 u x" assign x to the value of the node . "2 u v" print the maxim
View Solution →