komalnagpal / trees-3

Trees-3

Problem1 (https://leetcode.com/problems/path-sum-ii/)

Given a binary tree and a sum, find all root-to-leaf paths where each path's sum equals the given sum.

Note: A leaf is a node with no children.

Example:

Given the below binary tree and sum = 22,

 5

/
4 8 / /
11 13 4

/ \ / \

7 2 5 1 Return:

[

[5,4,11,2],

[5,8,4,5]

]

Problem2 (https://leetcode.com/problems/symmetric-tree/)

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).

For example, this binary tree [1,2,2,3,4,4,3] is symmetric:

1

/ \

2 2

/ \ / \

3 4 4 3 But the following [1,2,2,null,3,null,3] is not:

1

/ \

2 2

\ \

3 3 Note: Bonus points if you could solve it both recursively and iteratively.