silvergoni.builder()

https://programmers.co.kr/learn/courses/30/lessons/42577 1. 2022.04.01 시도 소요시간: - 분(기억안남) import java.util.*; class Box { Box[] boxes = new Box[10]; boolean isPhone; } class Solution { public boolean solution(String[] phone_book) { Arrays.sort(phone_book); Box wholeBox = new Box(); for (String each: phone_book) { Box temp = wholeBox; for (int i=0; i

https://programmers.co.kr/learn/courses/30/lessons/42576 1. 2022.04.01 시도 소요시간: -분(기억이 안남ㅠ) import java.util.Arrays; class Solution { public String solution(String[] participant, String[] completion) { String answer = ""; Arrays.sort(participant); Arrays.sort(completion); for (int i=0; i

https://leetcode.com/problems/unique-email-addresses/ 1. 2022.04.01 시도 소요시간: 10분(4분 문제 읽기, 6분 코딩) class Solution { public int numUniqueEmails(String[] emails) { Set ret = new HashSet(); for (String email: emails) { String rawLocalName = email.split("@")[0]; String domainName = email.split("@")[1]; String removeAfterPlus = rawLocalName.split("\\+")[0]; String removeDots = removeAfterPlus.replace(..

https://leetcode.com/problems/spiral-matrix-iii/ 1. 2022.03.31 시도 소요시간: 21분 class Solution { private String[] d = new String[]{"RIGHT", "DOWN", "LEFT", "UP"}; public int[][] spiralMatrixIII(int rows, int cols, int rStart, int cStart) { int rowSize = 1; int colSize = 1; int p=rStart; int q=cStart; int[][] ret = new int[rows*cols][2]; int directionIndex = 0; int counter = 0; ret[counter++] = new i..

https://leetcode.com/problems/spiral-matrix-ii/ 1. 2022.03.31 시도 소요시간: 5분 class Solution { private String[] d = new String[]{"RIGHT", "DOWN", "LEFT", "UP"}; public int[][] generateMatrix(int n) { int rowSize = n; int colSize = n; int p = 0; int q = -1; int[][] matrix = new int[n][n]; int directionIndex = 0; int number = 1; while( rowSize != 0 || colSize != 0) { String direction = d[directionInde..

https://leetcode.com/problems/spiral-matrix/ 1. 2022.03.31 시도 소요시간: 11분 class Solution { private String[] d = new String[]{"RIGHT", "DOWN", "LEFT", "UP"}; public List spiralOrder(int[][] matrix) { int rowSize = matrix.length; int colSize = matrix[0].length; int p = 0; int q = -1; List ret = new ArrayList(); int directionIndex = 0; while ( rowSize !=0 && colSize != 0) { String direction = d[direc..

https://leetcode.com/problems/reverse-only-letters/ 1. 2022.03.30 시도 소요시간: 9분 class Solution { public String reverseOnlyLetters(String s) { int left = 0; int right = s.length() -1; String ls =""; String rs =""; while(left < right) { char lc = s.charAt(left); char rc = s.charAt(right); if (isEnglishLetter(lc) == false) { left++; ls = ls + lc; continue; } else if (isEnglishLetter(rc) == false) { r..

https://leetcode.com/problems/sum-of-left-leaves/ 1. 2022.03.30 시도 소요시간: 12분(iterative), 5분(recursive) // iterative class Solution { public int sumOfLeftLeaves(TreeNode root) { if (root == null) { return 0; } int sum = 0; if (root.left != null) { int left = sumOfLeftLeaves(root.left); if (root.left.left == null && root.left.right == null) { sum = left + root.left.val; } else { sum += left; } } i..

https://leetcode.com/problems/peak-index-in-a-mountain-array/ 1. 2022.03.29 시도 소요시간: 4분 class Solution { public int peakIndexInMountainArray(int[] arr) { int peak = -1; for (int i=0; i

https://leetcode.com/problems/search-in-a-binary-search-tree/ 1. 2022.03.29 시도 소요시간: 3분(recursive), 3분(iterative) // recursive class Solution { public TreeNode searchBST(TreeNode root, int val) { if (root == null) { return null; } if (root.val == val) { return root; } TreeNode left = searchBST(root.left, val); if (left != null) { return left; } TreeNode right = searchBST(root.right, val); if (ri..