From here I understood that the complexity of some static arr is O(1)

But for d,java,time-complexity"/>

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首页 > 解决方案 > 为什么 (List) 的运行时间复杂度) list.size() is O(1)?

From here I understood that the complexity of some static arr is O(1)

But for d

java - 为什么 (List) 的运行时间复杂度) list.size() is O(1)?

From here I understood that the complexity of some static arr is O(1)

But for d

问题描述

From here I understood that the complexity of some static arr is O(1)

But for dynamic array the size is never set, so how the complexity will be constant? Even Oracle documentation says so.

static int count =  0;
public static void main(String[] args) {
    List.of(1, 2, 3, 4, 5).forEach(x -> count++); // Java-10
    System.out.println(count);
}

this code should determine the size of the list, if this runs for O(n) times then why 

List.of(1, 2, 3, 4, 5).size();

is O(1)

Why does attribute splitting happen in BeautifulSoup?

I try to get the attribute of the parent element:

<div class="detailMS__incidentRow incidentRow--away odd">
    <div class="time-box">45'</div>
    <div class="icon-box soccer-ball-own"><span class="icon soccer-ball-own">&nbsp;</span></div>
    <span class=" note-name">(Autogoal)</span><span class="participant-name">
        <a href="#" onclick="window.open('/player/reynaldo/CxtEEPzE/'); return false;">Reynaldo</a>
    </span>
</div>

span_autogoal = soup.find('span', class_='note-name')
print(span_autogoal)
print(span_autogoal.find_parent('div')['class'])
# print(span_autogoal.find_parent('div').get('class')

Output:

<span class="note-name">(Autogoal)</span>
['detailMS__incidentRow', 'incidentRow--away', 'odd']

I know i can do something like this:

print(' '.join(span_autogoal.find_parent('div')['class']))

But i want to know why this is happening and is it possible to do this more correctly?

标签： javatime-complexity

解决方案

例如，在这里，ArrayList 将存储当前大小以使其立即可用。其他列表将类似，因为它是常见的优化。（例如LinkedList）

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