每日一题：大样本统计

题目链接：https://leetcode.cn/problems/statistics-from-a-large-sample/

直接按题意模拟遍历即可！

求中位数有个技巧：

	class Solution {
	public double[] sampleStats(int[] count) {
	int n = count.length;
	double sum = 0;
	int cnt = 0;
	int max = -1;
	int min = 256;
	int maxCount = 0;
	int mode = 0;

	for (int i = 0; i < n; ++i) {
	if (count[i] > 0) {
	max = Math.max(i, max);
	min = Math.min(i, min);
	sum += (double) i * count[i];
	cnt += count[i];
	if (count[i] > maxCount) {
	maxCount = count[i];
	mode = i;
	}
	}
	}

	double median = 0;

	// 寻找第 cnt / 2 + 1 个数
	int k = 0;
	int mid = cnt / 2 + 1;
	while (k < n) {
	if (mid <= count[k]) {
	median = k;
	if (cnt % 2 == 0) {
	// 偶数个
	if (mid == 1) {
	// 在前一个桶内
	--k;
	while (k > 0 && count[k] <= 0) --k;
	}
	median = (median + k) / 2;
	}
	break;
	}
	mid -= count[k++];
	}

	return new double[] {min, max, sum / cnt, median, mode};
	}
	}