swift应用

一、swift实例

1、冒泡法

(1).只能按一种方式排序

//冒泡
var a = [2,8,4,10,31,12]
for i in 0..<a.count - 1 {//循环多少次
    for j in 0..<(a.count - i - 1) {//比较多少次
        //比较转换位置
        if (a[j] > a[j+1]) {
            let temp = a[j]
            a[j] = a[j+1];
            a[j+1] = temp;
        }
    }
}
print(a)

(2).使用闭包

//函数
func upsort(num:Int,num1:Int)->Bool{
    return num > num1 ? true : false
}
//闭包
let downsort:(Int,Int)->Bool = {
    return $0 < $1
}
var arr2 = [2,5,1,4,7,6,0,18];
func sortArray(sortFun:(Int,Int)->Bool) {
    for i in 0..<arr2.count - 1 {
        for j in 0..<arr2.count - 1 - i {
            if (sortFun(arr2[j],arr2[j+1])){
            let temp=arr2[j]
            arr2[j]=arr2[j+1]
            arr2[j+1] = temp
            }
        }
    }
   print(arr2)
}
//调用函数升序排列
sortArray(sortFun:upsort)
//使用闭包降序
sortArray(sortFun:downsort)

2、层级遍历

import Foundation

class Node: NSObject {
    //!强制拆包（解析）
    var date: Int!
    var leftChild: Node? //？可选类型
    var rightChild: Node?
    
}
//创建类对象 
var node1 : Node = Node()
node1.date = 4

var node2 : Node = Node()
node2.date = 5

var node3 : Node = Node()
node3.date = 6

var node4 : Node = Node()
node4.date = 7

var node5 : Node = Node()
node5.date = 2
node5.leftChild = node1
node5.rightChild = node2

var node6 : Node = Node()
node6.date = 3
node6.leftChild = node3
node6.rightChild = node4

var node7 : Node = Node() //根节点
node7.date = 1
node7.leftChild = node5
node7.rightChild = node6
//定义空数组，将节点和根节点放进数组然后输出数组
func readDate(node : Node){
    var arr = [Node]()
    arr.append(node) //插入节点
    while arr.count > 0 {
        let t = arr[0]
        if let _ = t.leftChild {//可选绑定，判断是否有左右子叶，如果有添加到数组中
            arr.append(t.leftChild!)
        }
        if let _ = t.rightChild{
            arr.append(t.rightChild!)
        }
        print(t.date)
        arr.remove(at: 0)
       
    }
}
readDate(node:node7)