SDE - 2

Given a string “STR”, you need to return all the possible non-empty subsequences with distinct characters. You can return the strings in any order.

Note:

If the same string can be generated multiple times, return them multiple times. 

A subsequence is a sequence that can be derived from another sequence by deleting some or no elements without changing the order of the remaining elements.

For eg. Let the input string be 'cbc'. Then all the subsequences with distinct characters will be - ['c', 'bc', 'c', 'cb', 'b'].

Ninja is the steel factory owner, and there are 'N' workers working at that factory. Each worker has his own working time, and it is provided in the array 'intervals' where 'INTERVALS[i][0]' gives the start time of the 'i'th worker and 'INTERVALS[i][1]' gives the end time of the 'i'th worker.

Ninja does not want to allow more than one worker to work at the same time, so he needs your help to find the minimum number of workers he needs to reschedule their work time so as there are non-overlapping working times in any two workers.

Example:

Input: 'INTERVALS' = [[1, 2], [1, 3], [2, 3], [3, 4]]
Output: 1

After rescheduling the worker with the interval [1, 3] it is possible to get the non-overlapping working times.

You are given an integer 'N'. For a given 'N' x 'N' chessboard, find a way to place 'N' queens such that no queen can attack any other queen on the chessboard.

A queen can be killed when it lies in the same row, or same column, or the same diagonal of any of the other queens. You have to print all such configurations.

You are a student of Netaji Subhas Institute of Technology. You have to take ‘N’ number of courses labelled from 1 to N to complete your B.Tech Degree.

Some courses may have prerequisites, for example, to take course 1 you have to first take course 2, which is expressed as a pair: [1, 2]. Now, your task is to find is it possible for you to finish all courses.

Note: There are no duplicate pairs in the prerequisites array.

For example-

If N = 2 and prerequisite = [[1, 2]]. Then, there are a total of 2 courses you need to take. To take course 1 you need to finish course 2. So, it is possible to complete all courses. 

We have a collection of 'N' stones, each stone has a positive integer weight.

On each turn, we choose the two heaviest stones and smash them together. Suppose the stones have weights 'x' and 'y' with 'x' <= 'y'. The result of this smash will be:

1. If 'x' == 'y', both stones are totally destroyed;

2. If 'x' != 'y', the stone of weight 'x' is totally destroyed, and the stone of weight 'y' has a new weight equal to 'y - x'.

In the end, there is at most 1 stone left. Return the weight of this stone or 0 if there are no stones left.

create the lld for splitwise(the invoice part).

HLD of my old project and SDLC lifecycle