knowsudhanshu

func waysToScore(n: Int) -> Int {

    var arr: [Int] = [Int](repeating: 0, count: n + 1)
    arr[0] = 1
    for index in 1...n {
        // print("index: \(index)")
        if index - 3 >= 0 {
            // print("index - 3 > 0 ----Start--------")
            // print("\(arr[index])")
            // print("\(arr[index - 3])")

knowsudhanshu

let input = [
[1,3,5,8],
[4,2,1,7],
[4,3,2,3]
]

/*
// Recursion
func maxPathCost(input: [[Int]], m: Int, n: Int) -> Int {
    if m == 0 && n == 0 {

knowsudhanshu

let input = [
[1,3,5,8],
[4,2,1,7],
[4,3,2,3]
]

func minPathCost(input: [[Int]], m: Int, n: Int) -> Int {
    if m == 0 && n == 0 {
        return input[0][0]
    }    

knowsudhanshu

func getCelebrity(input: [[Int]]) -> Int {

    // Add person to stack
    var stack: [Int] = []
    for i in  0..<input.count {
        stack.append(i)
    }
    // pick a person and check with others
    while stack.count > 1 {

knowsudhanshu

infix operator !!
func !!<T>(lhs: T?, rhs: T) -> T {
    guard let lhs = lhs else {
        return rhs
    }
    return lhs
}
var someVar: String? = "has value"
print(someVar !! "no value")

knowsudhanshu

struct BiometricIDHandler {
    static func authenticateWithBiometrics() {
        
        let laContext = LAContext()
        
        var error: NSError?
        
        if laContext.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics,
                                       error: &error) {

knowsudhanshu

protocol Weakifiable where Self: class {}

extension NSObject: Weakifiable {}

extension Weakifiable {
  func weakify<T>(_ code: @escaping (Self, T) -> Void) -> (T) -> Void {
    {
      [weak self] (data) in 
      
      guard let self = self else { return }

knowsudhanshu

func literalExpressionExample() {
  /// #file     : String, it represents the path to the file
  /// #function : String, name (with signature) of the function
  /// #line     : Int, line number on which it appears
  
  print(#file + " : " #function + " : " + " : " + \(#line))
  
}

knowsudhanshu

protocol A {
    var someVar: String { get set }
    func someFunc()
}
protocol B {
    var someVar: String { get set }
    func someFunc()
}
struct C: A, B {
    @_implements(A, someVar)

knowsudhanshu

extension Sequence {
    func myFilter(_ operation: (_ val: Element) -> Bool) -> [Element] {
        var output: [Element] = []
        
        for item in self {
            if operation(item) {
                output.append(item)
            }
        }
        return output