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Stream is an iterator that allows you to refer to the storage elements of a collection one by one and process them in a lambda expression, which has been added since Java 8. It acts similar to an Iterator, but the difference is that the code can be made more concise by providing the element handling code in a lambda expression, and that parallelism is easy because it uses an internal iterator. I..

var : 1. can be declared with any datatype for a local variable public class VarKeyword { public static void main(String[] args) { // local variale var a = 10; // local variale var b = 1.2; // Java can infer what type is declared System.out.println(String.format("result:\n%d", a)); System.out.println(b); } }2. can not be used in an instance and global variable 3. cannot be used in a Generic type..

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the same type of brackets. Open brackets must be closed in the correct order. Example 1: Input: s = "()" Output: true Example 2: Input: s = "()[]{}" Output: true Example 3: Input: s = "(]" Output: false class Solutio..

Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Example 1: Input: strs = ["flower","flow","flight"] Output: "fl" Example 2: Input: strs = ["dog","racecar","car"] Output: "" Explanation: There is no common prefix among the input strings. class Solution(object): def longestCommonPrefix(self, strs): resu..

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, 2 is written as II in Roman numeral, just two one's added together. 12 is written as XII, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II. Roman numerals are usually written largest to smallest from left to right. Howeve..

Given an integer x, return true if x is palindrome integer. An integer is a palindrome when it reads the same backward as forward. For example, 121 is a palindrome while 123 is not. flag = False x = str(x) if len(x) == 1: return True for i in range(len(x)//2): if x[i] == x[-i - 1]: flag = True else: flag = False break return flag

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. You may assume that each input would have exactly one solution, and you may not use the same element twice. You can return the answer in any order. class Solution(object): def twoSum(self, nums, target): """ :type nums: List[int] :type target: int :rtype: List[int] """ t = ta..

Factor String StringBuilder StringBuffer Storage Area String Pool Heap Area Heap Area Mutability Immutable Mutable Mutable Performance slow Fast middle Java Version 1.0 1.5 1.2

Java Development Kit(JDK) Java Runtime Environment(JRE) Java Virtual Machine(JVM) JRE + Development tools JVM + Libraries to execute the application Runtime environment to execute Java byte code JRE, JavaDoc, compiler, debuggers, and so on. software package(Java class libraries, JVM, and so on.) Specification, Implement, and Runtime Instance.

xxxx.py대신 xxxx.spec 열어 붉은색 부분 추가후, pyinstaller xxxx.spec로 실행. xxxx.spec 내용 # -*- mode: python ; coding: utf-8 -*- import sys sys.setrecursionlimit(5000) block_cipher = None