Only Code

Activity Selection problem

Activity selection problem is the problem of selecting the largest set of mutually exclusive activities. Each activity has its own starting time si and finish time fi. No two activities can share the resource at any time point.

Greedy approach

Custom Sort String – LeetCode Solution [Medium]

You are given two strings order and t. All the words of order are unique and were sorted in some custom order previously.

Competitive Programming, Greedy approach

Job sequencing problem

There are n jobs to be processed on a machine. Each job i has a deadline and a profit. Profit is earned if the job is completed by its deadline. Job is completed if it is processed on a machine for unit time.

Greedy approach

Decode Ways – LeetCode Solution [Medium]

A message containing letters from A-Z can be encoded into numbers. To decode an encoded message, all the digits must be grouped then mapped back into letters using the reverse of the mapping

Dynamic Programming

Greedy approach vs Dynamic Programming

Greedy approach and Dynamic programming both are used for solving optimisation problems. However often we need to use DP since optimal solution cannot be guaranteed by a greedy algorithm.

Dynamic Programming, Greedy approach

Knapsack problem (Finding selected items)

A little recap: Let given weights & values of n items to be put in a knapsack of capacity W ie.

Dynamic Programming

Knapsack Problem (Dynamic Programming)

An optimal solution to problem contain optimal solution to subproblems. To consider all subset of items, 2 cases for every item arises

Dynamic Programming

Multiset Partitioning Problem

The number of possible partition of a set of n elements is B(n) known as Bell number. As we know, this problem is NP-Complete i.e. it has non-polynomial time solution.

Backtracking & Recursion, Mathematics

A Chocolate Fiesta | HackerRank

While it is given that if two numbers are same in the given set, they have different colors. It means that if a1 = a2, then choosing a1 and choosing a2 will be considered as different sets.

Competitive Programming, Mathematics

Quicksort worst-case and averages-case analysis

Quick Sort is capable of sorting a list of data elements significantly faster (twice or thrice faster) than any of the common sorting algorithms and that’s why it is the favourite topic of interviewers.

Algorithms, Sorting