例如:s = “LEETCODE“ ,则其中 “L“, “T 2023-05-08:我们定义了一个函数 countUniqueChars(s) 来统计字符串 s 中的唯一字符, 并返回唯一字符的个数。 例如:s = "LEETCODE" ,则其中 "L", "T","C","O","D" 都是唯一字符, 因为它们只出现一次,所以 countUniqueChars(s) = 5
正确使用索引 准备400万测试数据 /*建库javacode2018*/ DROP DATABASE IF EXISTS javacode2018; CREATE DATABASE javacode2018...多个索引时查询如何走?...结论:索引字段使用函数查询使索引无效。...结论:索引字段使用了函数将使索引无效。...总结一下使用索引的一些建议 在区分度高的字段上面建立索引可以有效的...
Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. 给一个字符串,返回第一个不重复的字符的index,要是没有的话就返回-1 //第一次做,感觉巨简单,设一个set,一旦contains,就用striing.indexOf()---还能用上不熟悉的函数,简直完...
标签: Java Python 算法 收藏 LeetCode 387: 字符串中的第一个唯一字符 First Unique Character in a String 题目: 给定一个字符串,找到它的第一个不重复的字符,并返回它的索引。如果不存在,则返回 -1。 Given a string, find the first non-repeating character in it and return it’s index. If it...
题目描述: Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: s = "leetcode" return 0. s = "loveleetcode", return 2. 解题思路: 开个26个数的数组,然后先对字符串过一遍,统计每个字母出现的次数,然后从头再国一...
Let’s take a look at number of ways we could create Unique Keys in Java java.util.UUID: cryptographically strong pseudo random number generator. Introduced in Java 5 java.rmi.server.UID: unique ID over time with respect to the host that it was generated on java.security.SecureRandom: pro...
现在总结一下unique,unique的作用是“去掉”容器中相邻元素的重复元素(不一定要求数组有序),它会把重复的元素添加到容器末尾(所以数组大小并没有改变),而返回值是去重之后的尾地址,下面举个例子。 由于返回的是容器末尾,所以如果想得到去重后的size,需要减去初始地址,lower_bound是得到地址,稍微不同。 如: ...
UUID Creator is a Java library for generating Universally Unique Identifiers. It generates all standard identifiers from UUIDv1 to UUIDv7. It also provides an alternative to the classic JDK's UUID (alt.GUID), many codecs (codec.*) and several utilities (
Sample Code ApplyUniqueValuesWithAlternateSymbolsSample.java Use dark colors for code blocksCopy /** Copyright 2022 Esri.** Licensed under the Apache License, Version 2.0 (the "License"); you may not* use this file except in compliance with the License. You may obtain a copy of* the Licens...
NotificationsYou must be signed in to change notification settings Fork9 Star130 main 1Branch5Tags Code Folders and files Name Last commit message Last commit date Latest commit myohn-paypal Update README for 1.1.3 release Oct 23, 2024