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整数流中的最大值和最小值

[英]Max & Min in stream of integers

原文 2012-12-03 07:33:43 5 1 java/ max/ min/ data-stream

Given a stream of integers (I can only go through them once), what is the best solution to find maximum and minimum? 给定整数流（我只能遍历一次），找到最大值和最小值的最佳解决方案是什么？ I suppose that in case I have enough time to proccess each number the easiest solution is to simply keep min and max values in a separate variables, but what is the best approach if I'm unable to proccess every single one of them? 我想，如果我有足够的时间处理每个数字，最简单的解决方案是将最小值和最大值保留在单独的变量中，但是如果我无法处理每个数字，那么最好的方法是什么？ Is there some better solution than simply keep max and min variables and skip for example every second number? 有没有比仅保留max和min变量并跳过例如第二个数字更好的解决方案？

1 个解决方案

If you want the true maximum and minimum, just track them with variables. 如果您想要真实的最大值和最小值，只需使用变量跟踪它们即可。

Depending on your input data, a probabilistic min/max may be "accurate enough". 根据您的输入数据，概率的最小值/最大值可能“足够准确”。 So if you only look at every number with 50% chance, then you probably have only a 50% of having the exact min or max. 因此，如果您仅以50％的机会查看每个数字，那么您可能只有50％的确切最小值或最大值。 But maybe already a 75% chance of having at least the second largest/smallest etc. However, computing the random number to do an unbiased sampling is already more expensive than looking at all numbers for min/max. 但是也许至少有第二大/最小的等概率已经有75％的可能性。但是，计算随机数进行无偏采样比查看所有数字的最小值/最大值已经更加昂贵。 Skipping every second is dangerous: there might be an even/odd pattern in the data that screws you badly. 每秒跳过是很危险的：数据中可能存在偶数/奇数模式，可能会严重损坏您。