룬아님의 취중코딩

kotlin으로 개발을 할때에 something?.let{} 이런 류의 코드를 많이 사용하게 된다. 그런데 변수 하나만 null 체크를 하는 것이 아니라 2개 이상 체크하고 싶으면 어떻게 해야할까? 하지만 Kotlin에서 직접적으로 지원하는 extension이 없기 때문에 https://stackoverflow.com/a/55736101 Multiple variable let in Kotlin Is there any way to chain multiple lets for multiple nullable variables in kotlin? fun example(first: String?, second: String?) { first?.let { second?.let { // Do something... ..

Nesting A string S consisting of N characters is called properly nested if: S is empty; S has the form "(U)" where U is a properly nested string; S has the form "VW" where V and W are properly nested strings. For example, string "(()(())())" is properly nested but string "())" isn't. Write a function: class Solution { public int solution(String S); } that, given a string S consisting of N charac..

StoneWall You are going to build a stone wall. The wall should be straight and N meters long, and its thickness should be constant; however, it should have different heights in different places. The height of the wall is specified by an array H of N positive integers. H[I] is the height of the wall from I to I+1 meters to the right of its left end. In particular, H[0] is the height of the wall's..

Fish You are given two non-empty arrays A and B consisting of N integers. Arrays A and B represent N voracious fish in a river, ordered downstream along the flow of the river. The fish are numbered from 0 to N − 1. If P and Q are two fish and P < Q, then fish P is initially upstream of fish Q. Initially, each fish has a unique position. Fish number P is represented by A[P] and B[P]. Array A cont..