Given an integer ‘N’ representing the number of pairs of parentheses, Find all the possible combinations of balanced parentheses with the given number of pairs of parentheses.
Note :
Conditions for valid parentheses:
1. All open brackets must be closed by the closing brackets.

2. Open brackets must be closed in the correct order.

You are given a sorted array 'A' of length 'N', two integers 'K' and 'X'. Your task is to print 'K' integers closest to 'X', if two integers are at the same distance return the smaller one.
The output should also be in sorted order
Note:
An integer 'a' is closer to 'X' than an integer 'b' if: 
|a - X| < |b - X| or ( |a - X| == |b - X| and a < b )

Given a binary tree with ‘root’. Your task is to find the sum of all the left leaf nodes.
Properties of leaf:-
In a binary tree, a leaf is a node such that it does not have any children. Node ‘1’ is always the root of the binary tree. Left leaves are those nodes that are the left child of their parent and a leaf node