TheNova22

// vim: syntax=swift
class Node{
    var key : Int
    var val : Int
    var pre: Node?
    var next : Node?
    init(_ key : Int , _ val : Int){
        self.key = key
        self.val = val
    }

TheNova22

// vim: syntax=swift
func numIslands(_ grid: [[Character]]) -> Int {
    guard grid.count > 0 else { return 0 }
    guard grid[0].count > 0 else { return 0 }
    var grid = grid
    var islandCounter = 0
    for i in 0..<grid.count{
        for j in 0..<grid[i].count{
            if grid[i][j] == "1"{
                islandCounter += 1

TheNova22

	// vim: syntax=swift
public class TreeNode {
     public var val: Int
     public var left: TreeNode?
     public var right: TreeNode?
     public init() { self.val = 0; self.left = nil; self.right = nil; }
     public init(_ val: Int) { self.val = val; self.left = nil; self.right = nil; }
     public init(_ val: Int, _ left: TreeNode?, _ right: TreeNode?) {
         self.val = val
         self.left = left

TheNova22

	// vim: syntax=swift
func binarySearch<T : Equatable & Comparable>(_ arr:[T] , _ val : T)->Bool{
    var l = 0
    var h = arr.count - 1
    while(l < h){
        let m = l + (h-l)/2
        if arr[m] == val{
            return true
        }
        else if arr[m] < val{

TheNova22

	// vim: syntax=swift
public class TreeNode {
     public var val: Int
     public var left: TreeNode?
     public var right: TreeNode?
     public init() { self.val = 0; self.left = nil; self.right = nil; }
     public init(_ val: Int) { self.val = val; self.left = nil; self.right = nil; }
     public init(_ val: Int, _ left: TreeNode?, _ right: TreeNode?) {
         self.val = val
         self.left = left

TheNova22

	// vim: syntax=swift
func solveSudoku(_ board: inout [[Character]]) {
    cansolve(&board)
}
func cansolve(_ board : inout [[Character]])->Bool{
    for i in 0..<9{
        for j in 0..<9{
            if board[i][j] == "."{
                for char in "123456789"{
                    if validPlacement(&board, i, j, char){

TheNova22

	// vim: syntax=swift
func solveNQueens(_ n: Int) -> [[String]] {
    var arr : [Int] = []
    var res : [[Int]] = []
    doer(n, 0, &arr, &res)
    var ans : [[String]] = []
    for i in 0..<res.count{
        ans.append([])
        for j in 0..<res[i].count{
            var st = ""

TheNova22

	// vim: syntax=swift
func anagram<C: Collection>(items: C) -> [[C.Iterator.Element]] {
    var scratch = Array(items)
    var result: [[C.Iterator.Element]] = []
    func heap(_ n: Int) {
        if n == 1 {
            result.append(scratch)
            return
        }

TheNova22

	// vim: syntax=swift
func gcd(_ a : Int, _ b : Int)->Int{
    if b == 0{
        return a
    }
    return gcd(b, a%b)
}
func lcm(_ a : Int , b : Int)->Int{
    return (a*b)/gcd(a, b)
}

TheNova22

	// vim: syntax=swift
func letterIndex(_ letter: Character) -> Int {
    return Int(letter.unicodeScalars.first!.value) - Int(Unicode.Scalar("a").value)
}