.Net Core 笔试1

1、用两个线程一个输出字母一个输出数字，交替输出Chat数组

            char[] aI = "1234567".ToCharArray();char[] aC = "ABCDEFG".ToCharArray();Task task1 = null;Task task2 = null;task1 = Task.Run(() =>{foreach (var item in aI){Console.WriteLine(item);task1.Wait(100);}});task2 = Task.Run(() =>{foreach (var item in aC){Console.WriteLine(item);task2.Wait(100);}});Task.WaitAll(task1, task2);Console.ReadLine();

2、用C#代码获取文件夹里及子文件夹所有文件名

        static void Main(string[] args){string filePath = @"E:\笔记";string[] strs = Directory.GetFiles(filePath, "*", SearchOption.AllDirectories);foreach (var item in strs){Console.WriteLine(item);}}

3、二分查找

        //二分查找public static int Erfen(int[] ints, int target){int left = 0, right = ints.Length - 1;while(left < right){int mid = left + (right - left) / 2;if (ints[mid] == target){return mid;}else if (ints[mid] < target){left = mid + 1;}else{right = mid - 1;}}return -1;}

4、斐波那契数列

using System.Collections;
using System.Text.Json;
namespace Test1
{internal class Program{static void Main(string[] args){Console.WriteLine("Feibo1");Console.WriteLine(Feibo1(1));Console.WriteLine(Feibo1(2));Console.WriteLine(Feibo1(3));Console.WriteLine(Feibo1(4));Console.WriteLine(Feibo1(5));Console.WriteLine("Feibo2");Console.WriteLine(Feibo2(1));Console.WriteLine(Feibo2(2));Console.WriteLine(Feibo2(3));Console.WriteLine(Feibo2(4));Console.WriteLine(Feibo2(5));Console.WriteLine("Feibo3");foreach (var item in Feibo3().Take(10)){Console.WriteLine(item);//斐波那契数列}}//递归public static int Feibo1(int n){if (n == 1){return 0;}if (n == 2 || n == 3) { return 1; }if (n > 3){return Feibo1(n-2)+Feibo1(n-1);}return 0;}//迭代循环public static int Feibo2(int n){if (n == 1){return 0;}if (n == 2) { return 1; }int first = 0, second = 1, next = 0;for (int i = 3; i <= n; i++){next = first + second;first = second;second = next;}return next;}//public static IEnumerable<int> Feibo3(){var (x, y) = (0, 1);yield return x;yield return y;while (true){(x, y) = (y, x + y);yield return y;}}}
}