SDE - 1

Ninja went to a school as an invigilator for an exam the seats in the room were mentioned with the number and they form a tree-like structure so he started thinking of a solution so that he allocated seats to students in such a way that no students would sit adjacent to each other.

So help our ninja write a code for the problem so he is able to count the maximum number of seats available for the students that no student can sit adjacent to each other.

So your task is to write a code that can find the maximum subset of a node in a given binary tree where there is no edge between any two nodes of the subset.

For example, consider the following binary tree. The largest subset set is {1, 5, 6, 7} and the size of the subset is 4.

You have been given a directed graph of 'V' vertices and 'E' edges.

Your task is to count the total number of ways to reach different nodes in the graph from the given source node ‘S’. A way is called as different from others if the destination node or used edges differ.

As the total number of such ways can be large, print the total ways modulo 10 ^ 9 + 7.

Note:

1. Include the source node as a destination also.
2. There are no cycles in the given graph.

There are ‘N’ cities numbered from 0 to ‘N’ - 1 and ‘M’ river connecting two cities in a Starlink Kingdom. The only way to travel from one city to another is by swimming through a river. Ninja is on a vacational journey and wants to do ‘Q’ travel. The energy required to swim against the river is ‘w’ and with the flow of river is zero, it means if the flow of river is from city ‘u’ to ‘v’ then the energy required to swim from ‘v’ to ‘u’ is ‘w’. Ninja has special power to reverse the direction of flow of water in the river. Ninja wants to minimize his energy consumption for this journey. Help Ninja to find the minimum energy required to complete his journey using his special power. He can reverse the direction of flow of any river any number of times before starting his journey( he may not use his power ).

Note : Energy consumption of one journey is equal to the sum of energy of each trip. There can be more than one river between any two cities.

Kevin has two sorted packs of cards. The first pack has N cards and the second one has M cards. Every card has an integer written on it. Now, you have to tell two things. First, how many different types of cards does Kevin have with both packs(union). Second, how many types both the packs have in common(intersection).

Note :

Two cards are said to be of different types if they have different numbers written on them.

You are given an array/list ‘BINARYNUMS’ that consists of ‘N’ distinct strings which represent all integers from 0 to N in binary representation except one integer. This integer between 0 to ‘N’ whose binary representation is not present in list ‘BINARYNUMS’ is called ‘Missing Integer’.

Your task is to find the binary representation of that ‘Missing Integer’. You should return a string that represents this ‘Missing Integer’ in binary without leading zeros.

Note

1. There will be no leading zeros in any string in the list ‘BINARYNUMS’.

Example:

Consider N = 5 and the list ‘binaryNums’=  [“0”, “01”, “010”, “100”, “101”].  This list consists of the binary representation of numbers [0, 1, 2, 4, 5]. Clearly, the missing number is 3 and its binary representation will be “11”. So you should return string “11”.

You have been given an array/list 'ARR' of integers. Your task is to find the second largest element present in the 'ARR'.

Note:

a) Duplicate elements may be present.

b) If no such element is present return -1.

Example:

Input: Given a sequence of five numbers 2, 4, 5, 6, 8.

Output:  6

Explanation:
In the given sequence of numbers, number 8 is the largest element, followed by number 6 which is the second-largest element. Hence we return number 6 which is the second-largest element in the sequence.

Ninja has a number ‘N’. He wants to print the pattern in such a way that the outer rectangle is of the number ‘N’ and the number goes on decreasing as we move inside the rectangles.

For example, if ‘N’ = 4, then pattern will be:

4 4 4 4 4 4 4 
4 3 3 3 3 3 4 
4 3 2 2 2 3 4 
4 3 2 1 2 3 4 
4 3 2 2 2 3 4 
4 3 3 3 3 3 4 
4 4 4 4 4 4 4