usk83

class Solution {
  func climbStairs(_ n: Int) -> Int {
    if n <= 3 {
      return n
    }
    var steps = [3, 1, 2]
    for step in 4...n {
      steps[step % 3] = steps[(step - 1) % 3] + steps[(step - 2) % 3]
    }
    return steps[n % 3]

usk83

class Solution {
  func findCheapestPrice(_ n: Int, _ flights: [[Int]], _ src: Int, _ dst: Int, _ K: Int) -> Int {
    var adj = [[(to: Int, price: Int)]](repeating: [], count: n)
    for flight in flights {
      adj[flight[0]].append((flight[1], flight[2]))
    }

    var current = [(src, 0)]
    var minPrices = [Int](repeating: -1, count: n)
    var stops = 0

usk83

import Foundation

func solveMinimumCostFlow() {
  // 1  ≤ 𝑁 ≤ 100,000, 𝑁 - 1 ≤ 𝑀 ≤ 200,000, 0 ≤ D ≤ 109
  let meta = readLine()!.split(separator: " ").compactMap { Int($0) }
  let n = meta[0]
  let m = meta[1]
  let d = meta[2]

  struct Pipe {

usk83

/*
 * > Runtime: 16 ms, faster than 100.00%
 * > Memory Usage: 21.2 MB, less than 100.00%
 */
class Solution {
  func twoCitySchedCost(_ costs: [[Int]]) -> Int {
    var left = [Int]()
    left.reserveCapacity(costs.count >> 1)
    var right = [Int]()
    right.reserveCapacity(costs.count >> 1)

usk83

class Solution {
  func canFinish(_ n: Int, _ edges: [[Int]]) -> Bool {
    var inDegrees = [Int](repeating: 0, count: n)
    var graph = [[Int]](repeating: [Int](), count: n)
    for edge in edges {
      inDegrees[edge[0]] += 1
      graph[edge[1]].append(edge[0])
    }

    var initialVs = [Int]()

usk83

import Foundation

/*
 * DFS
 * - Time: O(N)
 * - Space: O(N)
 */
func solveCyclicPermutationByDFS() {
  let t = Int(readLine()!)!
  for _ in 0..<t {

usk83

import Foundation

func readInput() -> ([[Int]], Set<Int>) {
  let meta = readLine()!.split(separator: " ").map { Int($0)! }

  var input = ([[Int]](repeating: [Int](), count: meta[0]), Set<Int>())
  let realNodes = readLine()!.split(separator: " ").map { Int($0)! }
  input.1 = Set<Int>(realNodes)

  for _ in 0..<meta[0] - 1 {

usk83

//
//  UF.swift
//  SwiftAlgorithmsDataStructures
//
//  Created by Derrick Park on 2/24/20.
//  Copyright © 2020 Derrick Park. All rights reserved.
//

import Foundation

usk83

import Foundation

func readTree() -> [[Int]] {
  let n = Int(readLine()!)!
  var tree = [[Int]](repeating: [Int](), count: n + 1)
  for _ in 1..<n {
    let nodes = readLine()!.split(separator: " ").map { Int($0)! }
    tree[nodes[0]].append(nodes[1])
    tree[nodes[1]].append(nodes[0])
  }

usk83

import Foundation

func findSubstring(_ text: String, _ pattern: String) -> String.Index? {
  return findSubstringBM(text, pattern)
}

func findSubstringBM(_ text: String, _ pattern: String) -> String.Index? {
  let pLength = pattern.count
  let tLength = text.count
  var table = [Character:Int]()