SDE - Intern

You are given a string encoded with a special algorithm. Your task is to decode the string and count the frequency of each letter from 'A' to 'Z' in the final decoded message.

The encoding rules are as follows:

• Single-Digit Characters: The letters 'A' through 'I' are represented by the digits 1 through 9 respectively.
• Double-Digit Characters: The letters 'J' through 'Z' are represented by two digits (10 through 26) followed by a # symbol. For example, 10# is 'J', 11# is 'K', and so on.
• Repetition: A character or character sequence can be followed by a repetition marker in the format [k], where k is an integer. This means the character decoded just before the [ appears k times. For example, 1[3] decodes to three 'A's, and 12#[2] decodes to two 'L's.
  

  Your function should not return the full decoded string (which could be very long). Instead, it must return an array or list of 26 integers, where the element at index 0 is the frequency of 'A', at index 1 is the frequency of 'B', and so on.

  
  

You are the network administrator for a campus with n buildings. A set of cables originally connected all buildings, forming a single connected network. Unfortunately, due to some damage, some of these cables are now broken.

You are given:

• n: The number of buildings (nodes), numbered 1 to n.
• edges: A list of all cables that are currently working.
• broken_edges: A separate list of the broken cables, along with the cost to repair each one.

Your task is to determine the minimum total cost to repair a selection of broken cables so that all n buildings are once again part of a single, fully connected network.

If it's impossible to connect all buildings even after repairing all broken cables, you should report it.

You are given an arbitrary binary tree consisting of N nodes, where each node is associated with a certain value, your task is to find the maximum width of the given tree.

Width of a binary tree is defined as the maximum width of all levels.

For example, consider the following binary tree:

For the above tree, width of level 1 is 1, width of level 2 is 2, width of level 3 is 3 and width of level 4 is 1. So the maximum width of the tree is 3.

Mr. X is a professional robber planning to rob houses along a street. Each house has a certain amount of money hidden.

All houses along this street are arranged in a circle. That means the first house is the neighbour of the last one. Meanwhile, adjacent houses have a security system connected, and it will automatically contact the police if two adjacent houses are broken into on the same night.

You are given an array/list of non-negative integers 'ARR' representing the amount of money of each house. Your task is to return the maximum amount of money Mr. X can rob tonight without alerting the police.

Note:

It is possible for Mr. X to rob the same amount of money by looting two different sets of houses. Just print the maximum possible robbed amount, irrespective of sets of houses robbed.

For example:

(i) Given the input array arr[] = {2, 3, 2} the output will be 3 because Mr X cannot rob house 1 (money = 2) and then rob house 3 (money = 2), because they are adjacent houses. So, he’ll rob only house 2 (money = 3)

(ii) Given the input array arr[] = {1, 2, 3, 1} the output will be 4 because Mr X rob house 1 (money = 1) and then rob house 3 (money = 3).

(iii) Given the input array arr[] = {0} the output will be 0 because Mr. X has got nothing to rob.