Merging Binary Trees - Amazon Top Interview Questions
Problem Statement :
Given two binary trees node0 and node1, return a merge of the two trees where each value is equal to the sum of the values of the corresponding nodes of the input trees. If only one input tree has a node in a given position, the corresponding node in the new tree should match that input node. Constraints n ≤ 100,000 where n is the number of nodes in node0 m ≤ 100,000 where m is the number of nodes in node1 Example 1 Input node0 = [0, [3, null, null], [2, [3, null, null], null]] node1 = [7, [5, null, null], [1, null, null]] Output [7, [8, null, null], [3, [3, null, null], null]] Example 2 Input node0 = [1, [2, [3, null, null], null], null] node1 = [4, null, [5, null, [6, null, null]]] Output [5, [2, [3, null, null], null], [5, null, [6, null, null]]]
Solution :
Solution in C++ :
Tree* solve(Tree* node0, Tree* node1) {
if (!node0)
return node1;
else if (!node1)
return node0;
else {
node0->val += node1->val;
auto left = solve(node0->left, node1->left);
auto right = solve(node0->right, node1->right);
node0->left = left;
node0->right = right;
return node0;
}
}
Solution in Python :
class Solution:
def solve(self, node0, node1):
if not node0:
return node1
if not node1:
return node0
node0.left = self.solve(node0.left, node1.left)
node0.val += node1.val
node0.right = self.solve(node0.right, node1.right)
return node0
View More Similar Problems
Maximum Element
You have an empty sequence, and you will be given N queries. Each query is one of these three types: 1 x -Push the element x into the stack. 2 -Delete the element present at the top of the stack. 3 -Print the maximum element in the stack. Input Format The first line of input contains an integer, N . The next N lines each contain an above mentioned query. (It is guaranteed that each
View Solution →Balanced Brackets
A bracket is considered to be any one of the following characters: (, ), {, }, [, or ]. Two brackets are considered to be a matched pair if the an opening bracket (i.e., (, [, or {) occurs to the left of a closing bracket (i.e., ), ], or }) of the exact same type. There are three types of matched pairs of brackets: [], {}, and (). A matching pair of brackets is not balanced if the set of bra
View Solution →Equal Stacks
ou have three stacks of cylinders where each cylinder has the same diameter, but they may vary in height. You can change the height of a stack by removing and discarding its topmost cylinder any number of times. Find the maximum possible height of the stacks such that all of the stacks are exactly the same height. This means you must remove zero or more cylinders from the top of zero or more of
View Solution →Game of Two Stacks
Alexa has two stacks of non-negative integers, stack A = [a0, a1, . . . , an-1 ] and stack B = [b0, b1, . . . , b m-1] where index 0 denotes the top of the stack. Alexa challenges Nick to play the following game: In each move, Nick can remove one integer from the top of either stack A or stack B. Nick keeps a running sum of the integers he removes from the two stacks. Nick is disqualified f
View Solution →Largest Rectangle
Skyline Real Estate Developers is planning to demolish a number of old, unoccupied buildings and construct a shopping mall in their place. Your task is to find the largest solid area in which the mall can be constructed. There are a number of buildings in a certain two-dimensional landscape. Each building has a height, given by . If you join adjacent buildings, they will form a solid rectangle
View Solution →Simple Text Editor
In this challenge, you must implement a simple text editor. Initially, your editor contains an empty string, S. You must perform Q operations of the following 4 types: 1. append(W) - Append W string to the end of S. 2 . delete( k ) - Delete the last k characters of S. 3 .print( k ) - Print the kth character of S. 4 . undo( ) - Undo the last (not previously undone) operation of type 1 or 2,
View Solution →