最新2022年数据结构与算法面试题高级面试题及附答案解析

package com.jingxuan.system;

public class Fenshu20 {
	public static void main(String[] args) {
		float fm = 1f;
		float fz = 1f;
		float temp;
		float sum = 0f;
		for (int i = 0; i < 20; i++) {
			temp = fm;
			fm = fz;
			fz = fz + temp;
			sum += fz / fm;
			System.out.println(fz + "/" + fm);
		}
		System.out.println("这个数列的前20项之和为" + sum);
	}
}

2.0/1.0
3.0/2.0
5.0/3.0
8.0/5.0
13.0/8.0
21.0/13.0
34.0/21.0
55.0/34.0
89.0/55.0
144.0/89.0
233.0/144.0
377.0/233.0
610.0/377.0
987.0/610.0
1597.0/987.0
2584.0/1597.0
4181.0/2584.0
6765.0/4181.0
10946.0/6765.0
17711.0/10946.0
这个数列的前20项之和为32.660263

import java.io.File;

public class ListFiles {
	public static void listAll(File directory) {
		if(!(directory.exists() && directory.isDirectory())) {
			throw new RuntimeException("目录不存在");
		}
		File[] files = directory.listFiles();
		
		for (File file : files) {
			System.out.println(file.getPath() + file.getName());
			if(file.isDirectory()) {
				listAll(file);
			}
		}
	}
	
	public static void main(String[] args) {
		File directory = new File("E:\\Program Files (x86)");
		listAll(directory);
	}
}

package com.jingxuan.system;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Sumloop {
	public static void main(String[] args) throws IOException {
		int s = 0;
		String output = "";
		BufferedReader stadin = new BufferedReader(new InputStreamReader(System.in));
		System.out.print("请输入a的值：");
		String input = stadin.readLine();
		for (int i = 1; i <= Integer.parseInt(input); i++) {
			output += input;
			int a = Integer.parseInt(output);
			s += a;
			System.out.println(output);
		}
		System.out.println("s=a+aa+aaa+aaaa+aa...a的值为：" + s);
	}
}

请输入a的值：6
6
66
666
6666
66666
666666
s=a+aa+aaa+aaaa+aa...a的值为：740736

package com.jingxuan.system;

import java.util.Scanner;

public class JiSuan {

	private static Scanner sc;

	public static void main(String[] args) {
		sc = new Scanner(System.in);
		System.out.println("请输入一个数字：");
		double num = sc.nextDouble();
		double sum = 0;
		if (num % 2 == 0) {
			for (int i = 2; i <= num; i = i + 2) {
				sum = sum + (1.0 / i);// 因为i为整数
			}
			System.out.println("输入的偶数运算和为" + sum);
		} else {
			for (int i = 1; i <= num; i = i + 2) {
				sum = sum + (1.0 / i);
			}
			System.out.println("输入的奇数运算和为" + sum);
		}
	}
}

请输入一个数字：
6
输入的偶数运算和为0.9166666666666666

import java.util.Arrays;

class Solution {
	
	public static void main(String[] args) {
		int[] nums = {6,7,8,9,9,10,12};
		System.out.println("开始位置与结束位置索引值：" + Arrays.toString(searchRange(nums, 9)));
	} 

	public static int[] searchRange(int[] nums, int target) {
		int start = binarySearch(nums, target, true);
		int end = binarySearch(nums, target, false) - 1;
		if (start <= end && end < nums.length && nums[start] == target && nums[end] == target) {
			return new int[] { start, end };
		}
		return new int[] { -1, -1 };
	}

	public static int binarySearch(int[] nums, int target, boolean lw) {
		int start = 0, end = nums.length - 1, result = nums.length;
		while (start <= end) {
			int midd = (start + end) / 2;
			if (nums[midd] > target || (lw && nums[midd] >= target)) {
				end = midd - 1;
				result = midd;
			} else {
				start = midd + 1;
			}
		}
		return result;
	}
}

开始位置与结束位置索引值：[3, 4]

import java.util.Random;

public class Demo16 {

	public static void main(String[] args) {
		int temp = 0;
		int arr[] = new int[12];
		Random r = new Random();
		for (int i = 0; i <= 10; i++)
			arr[i] = r.nextInt(1000);
		for (int i = 0; i <= 10; i++)
			System.out.print(arr[i] + "\t");
		for (int i = 0; i <= 9; i++)
			for (int k = i + 1; k <= 10; k++)
				if (arr[i] > arr[k]) {
					temp = arr[i];
					arr[i] = arr[k];
					arr[k] = temp;
				}
		System.out.println();
		for (int k = 0; k <= 10; k++)
			System.out.print(arr[k] + "\t");
		arr[11] = r.nextInt(1000);
		for (int k = 0; k <= 10; k++)
			if (arr[k] > arr[11]) {
				temp = arr[11];
				for (int j = 11; j >= k + 1; j--)
					arr[j] = arr[j - 1];
				arr[k] = temp;
			}
		System.out.println();
		for (int k = 0; k <= 11; k++)
			System.out.print(arr[k] + "\t");
	}
}

265	882	280	873	848	283	423	549	569	494	52	
52	265	280	283	423	494	549	569	848	873	882	
52	265	280	283	423	494	549	569	701	848	873	882