[MySQL] 쿼리 실행 계획

select_type

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[LeetCode] Word Break

139. Word Break

Given a string s and a dictionary of strings wordDict, return true if s can be segmented into a space-separated sequence of one or more dictionary words.

Note that the same word in the dictionary may be reused multiple times in the segmentation.

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[LeetCode] Maximal Square

221. Maximal Square

Given an m x n binary matrix filled with 0’s and 1’s, find the largest square containing only 1’s and return its area.

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[LeetCode] Group Anagrams

49. Group Anagrams

Given an array of strings strs, group the anagrams together. You can return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

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[LeetCode] Pairs of Songs With Total Durations Divisible by 60

1010. Pairs of Songs With Total Durations Divisible by 60

You are given a list of songs where the ith song has a duration of time[i] seconds.

Return the number of pairs of songs for which their total duration in seconds is divisible by 60. Formally, we want the number of indices i, j such that i < j with (time[i] + time[j]) % 60 == 0.

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[LeetCode] Kth Largest Element in an Array

215. Kth Largest Element in an Array

Given an integer array nums and an integer k, return the kth largest element in the array.

Note that it is the kth largest element in the sorted order, not the kth distinct element.

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[LeetCode] Tweet Counts Per Frequency

1348. Tweet Counts Per Frequency

A social media company is trying to monitor activity on their site by analyzing the number of tweets that occur in select periods of time. These periods can be partitioned into smaller time chunks based on a certain frequency (every minute, hour, or day).

For example, the period [10, 10000] (in seconds) would be partitioned into the following time chunks with these frequencies:

  • Every minute (60-second chunks): [10,69], [70,129], [130,189], …, [9970,10000]
  • Every hour (3600-second chunks): [10,3609], [3610,7209], [7210,10000]
  • Every day (86400-second chunks): [10,10000]

Notice that the last chunk may be shorter than the specified frequency’s chunk size and will
always end with the end time of the period (10000 in the above example).

Design and implement an API to help the company with their analysis.

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[LeetCode] Subarray Sum Equals K

560. Subarray Sum Equals K

Given an array of integers nums and an integer k, return the total number of continuous subarrays whose sum equals to k.

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[LeetCode] Minimum Remove to Make Valid Parentheses

1249. Minimum Remove to Make Valid Parentheses

Given a string s of ‘(‘ , ‘)’ and lowercase English characters.

Your task is to remove the minimum number of parentheses ( ‘(‘ or ‘)’, in any positions ) so that the resulting parentheses string is valid and return any valid string.

Formally, a parentheses string is valid if and only if:

  • It is the empty string, contains only lowercase characters, or
  • It can be written as AB (A concatenated with B), where A and B are valid strings, or
  • It can be written as (A), where A is a valid string.
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[LeetCode] Meeting Rooms II

253. Meeting Rooms II

Given an array of meeting time intervals intervals where intervals[i] = [starti, endi], return the minimum number of conference rooms required.

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