하이 나윤

https://leetcode.com/problems/longest-palindrome/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com /** 1. 문제 해석하기 가장 긴 palindrome 만들기 2. 문제 풀이 방향 홀수는 한개(가장 긴 홀수를 찾아야함) 짝수는 전부 하면 무조건 palindrome을 만들 수 있을 것 같음. */ c..

https://leetcode.com/problems/palindrome-number/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 내친김에 palindrome 하나 더 풀었다. 반씩 비교한 풀이 6ms class Solution { public boolean isPalindrome(int x) { String str = String...

https://leetcode.com/problems/palindrome-linked-list/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com palindrome에 대해서 잘 몰라서 풀이 방식에 대해 찾아보았다. 1. 절반으로 나눠서 비교하는 방법 2. 뒤집은 다음에 같은지 확인하는 방법 1번으로 푼 코드 8ms /** * Definit..

https://leetcode.com/problems/longest-common-prefix/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com /** 1. 문제 해석하기 가장 긴 공통 prefix를 찾는 문제이고 없으면 "" 반환 2. 문제 풀이 방향 이중 for문으로 풀고 만약 common prefix가 ""이면 바로 반환 최초 comm..

https://leetcode.com/problems/backspace-string-compare/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com class Solution { public boolean backspaceCompare(String s, String t) { List sList = getList(s); List tList ..

https://leetcode.com/problems/roman-to-integer/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com /** 1. 문제 해석하기 I, V, X, L, C, D, M 4 -> IIII x -> IV IV, IX XL, XC CD, CM 2. 문제 풀이 방향 단일 for문 현재 index와 다음 index를 두..

https://leetcode.com/problems/single-number/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 최초 풀이는 HashMap을 이용해서 배열의 요소의 개수를 체크한 후 개수가 1인 요소를 반환했다. 하지만 이렇게 풀이할 경우 공간 복잡도가 O(n)이었다. 문제에서는 공간복잡도 O(1)로 풀길 권장하고 있었기 ..

https://leetcode.com/problems/middle-of-the-linked-list/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 1. 전체값을 찾는다. 2. 전체값을 통해 중간값을 찾는다. 3. 중간값에 해당하는 노드는 재귀를 통해 찾는다. /** * Definition for singly-linked list. * ..

https://leetcode.com/problems/contains-duplicate/description/ LeetCode - The World's Leading Online Programming Learning Platform Level up your coding skills and quickly land a job. This is the best place to expand your knowledge and get prepared for your next interview. leetcode.com 중복을 찾는 문제의 경우 set을 애용하는 편이다. HashSet 이용 class Solution { public boolean containsDuplicate(int[] nums) { Set set =..

recursive way iterative way 내 풀이 /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode() {} * ListNode(int val) { this.val = val; } * ListNode(int val, ListNode next) { this.val = val; this.next = next; } * } */ class Solution { public ListNode reverseList(ListNode head) { if (head == null) { return head; } List nums = new ArrayList(); while(he..