SDE - 1

You are given a string 'str' and an integer ‘K’. Your task is to find the length of the largest substring with at most ‘K’ distinct characters.

For example:

You are given ‘str’ = ‘abbbbbbc’ and ‘K’ = 2, then the substrings that can be formed are [‘abbbbbb’, ‘bbbbbbc’]. Hence the answer is 7.

You are given a Binary Tree.

Return the length of the diameter of the tree.

Note :

The diameter of a binary tree is the length of the longest path between any two end nodes in a tree.

The number of edges between two nodes represents the length of the path between them.

Example :

Input: Consider the given binary tree:

Output: 6

Explanation:
Nodes in the diameter are highlighted. The length of the diameter, i.e., the path length, is 6.

You are given an array ‘ARR’ of ‘N’ integers and a target number, ‘TARGET’. Your task is to build an expression out of an array by adding one of the symbols '+' and '-' before each integer in an array, and then by concatenating all the integers, you want to achieve a target. You have to return the number of ways the target can be achieved.

For Example :

You are given the array ‘ARR’ = [1, 1, 1, 1, 1], ‘TARGET’ = 3. The number of ways this target can be achieved is:
1. -1 + 1 + 1 + 1 + 1 = 3
2. +1 - 1 + 1 + 1 + 1 = 3
3. +1 + 1 - 1 + 1 + 1 = 3
4. +1 + 1 + 1 - 1 + 1 = 3
5. +1 + 1 + 1 + 1 - 1 = 3
These are the 5 ways to make. Hence the answer is 5.

You have been given a binary tree of integers. You are supposed to find the left view of the binary tree. The left view of a binary tree is the set of all nodes that are visible when the binary tree is viewed from the left side.

Example:

The left view of the above binary tree is  {5, 7, 14, 25}.

You are given an array ‘ARR’ consisting of ‘N’ integers. Your task is to make all the numbers equal. You decrease one of the largest numbers present in the array into a number that is just lower than the maximum number in one step.

For example:

You are given ‘ARR’ = [5, 2, 3]
In the first step, you can change 5 to 3, so the new array is [3, 2,3].

In the second step, you can change the 3 to 2, then the array is [2, 2,3].

In the third step, you can change the 3 to 2, then the array is [2, 2, 2] 

Hence the answer is 3.

You are given an array/list ARR consisting of N integers. Your task is to find all the distinct triplets present in the array which adds up to a given number K.

An array is said to have a triplet {ARR[i], ARR[j], ARR[k]} with sum = 'K' if there exists three indices i, j and k such that i!=j, j!=k and i!=j and ARR[i] + ARR[j] + ARR[k] = 'K'.

Note:

1. You can return the list of values in any order. For example, if a valid triplet is {1, 2, -3}, then {2, -3, 1}, {-3, 2, 1} etc is also valid triplet. Also, the ordering of different triplets can be random i.e if there are more than one valid triplets, you can return them in any order.
2. The elements in the array need not be distinct.
3. If no such triplet is present in the array, then return an empty list, and the output printed for such a test case will be "-1".

You are given an array ‘A’ of length ‘N’ consisting only of positive integers. Your task is to make the given array a palindrome by using a minimum number of operations. In one operation, you can select two adjacent indexes and merge them by adding their values. After every operation, the length of the array decreases by one.

Note: An array of length ‘1’ is a palindrome.

For example:

Let’s say the array ‘A’ = [1, 2, 3, 4, 5], then after merging indexes 2 and 3, the array ‘A’ will look like [1, 5, 4, 5].