Category "algorithm"

Custom Hashing Algorithm

Out of sheer boredom, I decided to write a hashing algorithm in python. It all works, however I've got a couple problems: Results are similar (e.g. hash(1234)

Does the .includes method in JavaScript loop through the array and case O(n)?

Does the .includes method cause O(n^2) when run with another loop such as in this simple example? function myFn(){ let age = people.map(person => {

In SPFA Shortest Path Faster Algorithm why does it have to check if current vertex is in queue before adding it to queue?

procedure Shortest-Path-Faster-Algorithm(G, s) 1 for each vertex v ≠ s in V(G) 2 d(v) := ∞ 3 d(s) := 0 4 push s into Q 5 w

Throw an error if multiple shortest paths are found

Given an undirected weighted graph, a start, and an end point. You need to find the shortest path to that end point, but throw an error if multiple shortest pat

Initializing a variable with INT_MIN in Python 3.8 [duplicate]

About the code The maximum sum subarray problem is the task of finding a contiguous subarray with the largest sum, within a given one-dimensio

Optimal Selection for minimum total sum

This is a problem from competitive programmer's handbook: We are given the prices of k products over n days, and we want to buy each product exactly once. Howev

Working with small probabilities, via logs

Source: Google Code Jam. https://code.google.com/codejam/contest/10224486/dashboard#s=a&a=1 We're asked to calculate Prob(K successes from N trials) where

Largest Triple Products without using sort?

I implemented the Largest Triple Products algorithm, but I use sort which makes my time complexity O(nlogn). Is there a way to implement it without a temporary

Reasons for using a Bag in Java

I am currently studying about Algorithms & Data Structures and while I was reading over the Book of Algorithms 4th edition, I discovered the Bag data-struct

Extract the century of a date from a string

My task is to output the current century of a given date. The date can be represented as a string; for example, 19.03.2022. How can I retrieve the year and cent

Understanding the Big O for squaring elements in an array

I was working on a problem where you have to square the numbers in a sorted array on leetcode. Here is the original problem Given an array of integers A sor

How to approach this Dynamic Programming Meal Plan Problem?

I came across this problem in a practice interview. I don't want a direct answer, just some help with the intuition of the problem, both your brute force thinki

Is there a known algorithm for finding which K elements out of N elements have a sum that is closest to a whole number?

As a small example, say I have N=6 elements { 0.03, 0.25000039, 1.391, 500.1, 0.5000001, 1.75001 } and K=3 then the combination { 0.25000039, 0.5000001, 0.

count words in a string without using split

I have a problem on which I am working where I need to count the number of words in a string without using the split() function in Python. I thought of an appro

how to calculate XOR (dyadic) convolution with time complexity O(n log n)

“⊕” is the bitwise XOR operation. I think Karatsuba’s algorithm may be used to solve the problem, but when I try to use XOR instead of

Java: How to implement wildcard matching?

I'm researching on how to find k values in the BST that are closest to the target, and came across the following implementation with the rules: '?' Matches

How to generate the worst case for disjoint set with only path compression?

A disjoint set with only path compression implemented is like this: // In cpp. int Find(int x) { return f[x] == x ? x : f[x] = Find(f[x]); } int Union(int a, i

Amazon interview: Min stack

I recently had my Amazon interview for SDE. I was asked to design a stack which does push, pop and min in O(1). I got the logic and implemented the push of the

How to reduce the time complexity of this algorithm?

I provide two data structures, cart_info and map_case, and get the result real_combinationby the algorithm. This algorithm is implemented in python import itert

Finding the shortest path with only passing specific edge less or equal to one time in Graph

Given a undirected graph that it has ordinary edges and specific edges, our goal is to find the sum of the shortest path's weight between two vertices(start ve