SDE - Intern

You are given an array of coins ‘COINS’ of length ‘N’ and there are ‘S’ number of slots numbered from 1 to S such that 2*S >= N.

You have to place all N coins into some slots so that no slot contains more than two coins. After placing the coins you will calculate the AND sum as the sum of all the values obtained by performing the bitwise AND operation between the slot number and the value of the coin placed in that slot number .

You have to find AND sum between the coins and the slots.

Given a ‘N’ * ’M’ maze with obstacles, count and return the number of unique paths to reach the right-bottom cell from the top-left cell. A cell in the given maze has a value '-1' if it is a blockage or dead-end, else 0. From a given cell, we are allowed to move to cells (i+1, j) and (i, j+1) only. Since the answer can be large, print it modulo 10^9 + 7.

For Example :

Consider the maze below :
0 0 0 
0 -1 0 
0 0 0

There are two ways to reach the bottom left corner - 

(1, 1) -> (1, 2) -> (1, 3) -> (2, 3) -> (3, 3)
(1, 1) -> (2, 1) -> (3, 1) -> (3, 2) -> (3, 3)

Hence the answer for the above test case is 2.

You are the manager of a hotel having 10 floors numbered 0-9. Each floor has 26 rooms [A-Z]. You will be given a sequence of strings of the room where ‘+’ suggests the room is booked and ‘-’ suggests the room is freed. You have to find which room is booked the maximum number of times.

Note:

You may assume that the sequence is always correct, i.e., every booked room was previously free, and every freed room was previously booked.

In case, 2 rooms have been booked the same number of times, you have to return Lexographically smaller room.

A string 'a' is lexicographically smaller than a string 'b' (of the same length) if in the first position where 'a' and 'b' differ, string 'a' has a letter that appears earlier in the alphabet than the corresponding letter in string 'b'. For example, "abcd" is lexicographically smaller than "acbd" because the first position they differ in is at the second letter, and 'b' comes before 'c'.

For Example :

n = 6, Arr[] = {"+1A", "+3E", "-1A", "+4F", "+1A", "-3E"}

Now in this example room “1A” was booked 2 times which is the maximum number of times any room was booked. Hence the answer is “1A”.

You have been given an N-ary tree ‘N’ nodes with node ‘1’ as head of the tree. Encode the above N-ary tree into a binary tree such that if only the encoded binary tree was given to you, you could restore the N-ary tree from the encoded binary tree. You also need to write a function that could decode a given binary tree and return a N-ary tree as in input format.

Note:

There is no restriction on how you encode/decode the N-ary tree.

Example:

N-ary Tree is given as follows:-
6
1 -1 2 3 4 -1 5 -1 6 -1 -1 -1 -1
The above N-ary tree and its encoded binary tree can be represented as follows:-

The above binary tree can be represented as follows in their level order traversal:-
1
2 -1
5 3
-1 -1 6 4
-1 -1 -1 -1