daoseng33

class LeftAlignedCollectionViewFlowLayout: UICollectionViewFlowLayout {

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        let attributes = super.layoutAttributesForElements(in: rect)

        var leftMargin = sectionInset.left
        var maxY: CGFloat = -1.0
        attributes?.forEach { layoutAttribute in
            if layoutAttribute.frame.origin.y >= maxY {
                leftMargin = sectionInset.left

possen

import Foundation

func validateSudoku(array : [Int]) -> Bool {
    let width = 9
   
    func valueAtPos(x: Int, y: Int, array: [Int]) -> Int {
        return array[y * width + x]
    }
    

possen

// 
// Anagram finder.
//
// Description: takes a list of anagrams and outputs the words in the same order as they appear in original string.
// Also outputs all the matched words after that in the order they appear after that.
//
// Language: Swift 5
// Author: Paul Ossenbruggen
// Date: Dec 4, 2015
// 

possen

//
// Description: RandomArrays: pick randomly to build new array in two different ways. One a shuffle the other 
// picking from the array. Shuffle uses Fischer-Yates algorithm to generate uniform randomness. Allthough it 
// might be better to use Apple's Game kit function GKRandomSource.sharedRandom().arrayByShufflingObjectsInArray(array)
// if available in the OS release. Also this only works on arrays, if you want to shuffle any colletion type 
// it is possible to extend MutableCollectionType. 
//
// Author: Paul Ossenbruggen
//
// Date: Nov 20, 2015

possen

//
// Description: Shortest distance graph. Calculates the distances from a start node to any node in the graph.
// Date: Nov 18, 2015
//
// Language: Swift
//
// Author: Paul Ossenbruggen
//
struct Edge : Equatable, Hashable, CustomStringConvertible {
    let weight : Int

possen

//
// Description: Finds the sum of all elements that add up to the target value using dynamic programming.
// Note: input array must be non negative and constrained to a reasonable ranage because it uses target+1 memory 
//
// Language: Swift
//
// Author: Paul Ossenbruggen
// Date: Nov 10, 2015
//

possen

import Foundation

//
// Description; Various solutions for finding number change possibilities and minimum number of change possibilitis.
//
// Author: Paul Ossenbruggen
// Date: Nov 8, 2015
// Updated: June 8, 2020
// Language: Swift 5.3
// See comments below for problem statement.

possen

//
// Description Silly Hat village in Swift solution
//
// Author: Paul Ossenbruggen
// Date: Nov 8, 2015
// Language: Swift 2.1
// See comment below for problem statement.
//

import Foundation

possen

//
// Description Switch problem in Swift solution
//
// Author: Paul Ossenbruggen
// Date: Nov 8, 2015
// Language: Swift 2.1
// See comment below for problem statement. This solves the second version where we don't know the state
// of the switch at the beginning.
//

possen

// Description: Implementation of a Trie
//
// Language: Swift 2.1
// Author: Paul Ossenbruggen
// Nov 7, 2015

import Foundation

class Trie  {
    var last : Bool = false