algorithm/src/main/java/com/dota/Solution.java

package com.dota;

import org.apache.commons.collections4.list.TreeList;

import java.util.HashMap;

public class Solution {
	public static void main(String[] args) {
		var a = new TreeList<Integer>();
		a.add(1);
		a.add(2);
		a.add(1);
		System.out.println(a.get(2));
		Integer.bitCount(1231);
	}
	// 1423. 可获得的最大点数
	public int maxScore(int[] cardPoints, int k) {
		int max;
		int n = cardPoints.length;
		int len = n - k;
		int sum = 0;
		for (int cardPoint : cardPoints) {
			sum += cardPoint;
		}


		int temp = 0;
		for (int i = 0; i < len; i++) {
			temp += cardPoints[i];
		}

		max = temp;
		for (int i = len; i < n; i++) {
			temp -= cardPoints[i - len];
			temp += cardPoints[i];
			if (temp < max) {
				max = temp;
			}
		}

		return sum - max;
	}

	// 2048. 下一个更大的数值平衡数
	public int nextBeautifulNumber(int n) {
		while (!ok(++n)) {
		}
		return n;
	}

	private boolean ok(int n) {
		if (n == 0) {
			return false;
		}

		int[] dp = new int[10];
		while (n != 0) {
			int t = n % 10;
			dp[t]++;
			if (dp[t] > t) {
				return false;
			}

			n /= 10;
		}

		for (int i = 1; i < dp.length; i++) {
			if (dp[i] != 0 && dp[i] != i) {
				return false;
			}
		}

		return true;
	}
}

class Solution2 {
	public long beautifulSubarrays(int[] nums) {
		long count = 0;
		var map = new HashMap<Integer, Integer>();
		map.put(0, 1);
		var mask = 0;
		for (int num : nums) {
			mask ^= num;
			count += map.getOrDefault(mask, 0);
			map.put(mask, map.getOrDefault(mask, 0) + 1);
		}
		return count;
	}
}