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1. 문제 https://www.acmicpc.net/problem/1248 2. Note 2.1. 완전탐색 - 백트래킹 모든 경우의 수를 구하고 이를 문제의 조건과 비교하는 문제에 익숙해져서 그런지 이런 방식으로만 문제를 해결하려 했습니다. 당연하게도 시간초과를 받았습니다. 적절히 가지치기를 수행해서 문제의 조건에 어긋나는 경우를 사전에 제거하는 백트래킹으로 접근해야 했습니다. 2.2. 문제 접근 태도 문제를 풀 때, 먼저 제한 시간을 보고 입력을 어떤 알고리즘에 욱여넣을(?) 수 있는지 확인하곤 합니다. 시간복잡도 분석은 물론 중요합니다. 그러나 문제의 본질에 집중하지 않고 익숙해진 알고리즘 유형에 끼워맞춰서 시간 내에 풀 수 있는지 확인하는 나쁜 버릇이 들었습니다. 문제에 좀 더 집중해야 합니다. ..

Networks and the Internet For example, the Hypertext Transfer Protocol (HTTP) is a protocol for retrieving named resources (chunks of information, such as web pages or pictures). Most protocols are built on top of other protocols. HTTP treats the network as a streamlike device into which you can put bits and have them arrive at the correct destination in the correct order. As we saw in Chapter 1..

Code function parseExpression(program) { program = skipSpace(program); let match, expr; if (match = /^"([^"]*)"/.exec(program)) { expr = {type: "value", value: match[1]}; } else if (match = /^\d+\b/.exec(program)) { expr = {type: "value", value: Number(match[0])}; } else if (match = /^[^\s(),#"]+/.exec(program)) { expr = {type: "word", name: match[0]}; } else { throw new SyntaxError("Unexpected ..

But many programs interact with things outside of the processor. For example, they may communicate over a computer network or request data from the hard disk—which is a lot slower than getting it from memory. ... In part, this is handled by your operating system, which will switch the processor between multiple running programs. But that doesn’t help when we want a single program to be able to m..

https://stackoverflow.com/questions/37491626/where-does-a-javascript-closure-live Where does a JavaScript closure live? I wrote this code to teach myself about JavaScript closures: function1 = function(){ var variable = "foo" var function2 = function(argument){ console.log(variable + argument); } return stackoverflow.com https://stackoverflow.com/questions/111102/how-do-javascript-closures-work ..

Word Boundary \b JS 정규표현식에서 \b는 word boundary이며, 이름 그대로 word character(\w)의 경계를 말합니다. 즉, 문자열에서 어느 한쪽은 word character([_a-zA-Z0-9])이고 다른 쪽은 non-word character([^_a-zA-Z0-9])인 지점들은 모두 word boundary로 볼 수 있습니다. 또한, word character와 문자열의 시작(^) 또는 끝($)의 사이 역시 word boundary로 볼 수 있습니다. 주의할 점은 \b는 어떤 지점을 의미하므로 특정 문자와 매칭되는 것이 아니라는 겁니다. Non-word Boundary \B \B는 non-word boundary입니다. \B는 non-word character의 ..

A typical real program grows organically. New pieces of functionality are added as new needs come up. Structuring—and preserving structure—is additional work. It’s work that will pay off only in the future, the next time someone works on the program. So it is tempting to neglect it and allow the parts of the program to become deeply entangled. This causes two practical issues. First, understandi..

Regular expressions are both terribly awkward and extremely useful. Properly understanding regular expressions will make you a more effective programmer. Creating a regular expression A regular expression is a type of object. It can be either constructed with the RegExp constructor or written as a literal value by enclosing a pattern in forward slash (/) characters. let re1 = new RegExp("abc"); ..

Language But here JavaScript’s looseness is a hindrance. Its concept of bindings and properties is vague enough that it will rarely catch typos before actually running the program. And even then, it allows you to do some clearly nonsensical things without complaint, such as computing true * "monkey". ... But often, your nonsense computation will merely produce NaN (not a number) or an undefined ..

Code const roads = [ "Alice's House-Bob's House", "Alice's House-Cabin", "Alice's House-Post Office", "Bob's House-Town Hall", "Daria's House-Ernie's House", "Daria's House-Town Hall", "Ernie's House-Grete's House", "Grete's House-Farm", "Grete's House-Shop", "Marketplace-Farm", "Marketplace-Post Office", "Marketplace-Shop", "Marketplace-Town Hall", "Shop-Town Hall" ]; function buildGraph(edges)..