tolinwei

class Solution {
    int mod = (int) Math.pow(10, 9) + 7;
    int[][] directions = new int[][] {
        {-2, 1}, 
        {-2, -1},
        {2, -1},
        {2, 1},
        {-1, 2},
        {-1, -2},
        {1, 2},

tolinwei

public String alienOrder(String[] words) {
        if (words == null || words.length == 0) {
            return "";
        }
        // adjacency list
        Map<Character, List<Character>> graph = new HashMap<>();
        // for topology sort
        Map<Character, Integer> inDegree = new HashMap<>(); 
        
        // WRONG 2: still populate the graph and inDegree, or NLE in the topology sort later

tolinwei

class Solution {
    public int search(int[] nums, int target) {
        if (nums == null || nums.length == 0) {
            return -1;
        }
        
        // find pivot
        int left = 0;
        int right = nums.length - 1;
        while (left < right) {

tolinwei

public int leastInterval(char[] tasks, int n) {
    int[] counter = new int[26];
    int max = 0;  // 最多的字母的频数
    int maxCount = 0;  // 有几个这样子的字母
    for(char task : tasks) {
        counter[task - 'A']++;
        if(max == counter[task - 'A']) {
            maxCount++;
        }
        else if(max < counter[task - 'A']) {

tolinwei

public List<List<String>> accountsMerge(List<List<String>> accounts) {
    if (accounts == null || accounts.size() == 0) {
        return new ArrayList<>();
    }
    UnionFind uf = new UnionFind(10000);
    Map<String, String> emailName  = new HashMap<>();
    Map<String, Integer> emailId = new HashMap<>();
    Map<Integer, List<String>> tempRes = new HashMap<>();
    int index = 0;

tolinwei

class UnionFind {
    int[] parent;
    int[] rank;
    public UnionFind(int n) {
        parent = new int[n];
        rank = new int[n];
        for (int i = 0; i < n; i++) {
            parent[i] = i;
        }
    }

tolinwei

public List<Integer> distanceK(TreeNode root, TreeNode target, int K) {
    Map<Integer, Integer> map = new HashMap<>();  // distance to target from root
    find(root, target, map);

    System.out.println("Map");
    for (Map.Entry<Integer, Integer> entry : map.entrySet()) {
        System.out.println(entry.getKey() + " ->" + entry.getValue());
    }
    List<Integer> res = new ArrayList<>();
    helper(root, target, K, map.get(root.val), map, res);

tolinwei

public void flatten(TreeNode root) {
    while (root != null) {
        if (root.left != null) {
            // find the right most in left subtree
            TreeNode rightMostInLeft = root.left;
            while (rightMostInLeft.right != null) {
                rightMostInLeft = rightMostInLeft.right;
            }
            rightMostInLeft.right = root.right;
            root.right = root.left;

tolinwei

{
    "slots": [
        "SportsTeam"
    ],
    "prioritizedAuthorities": [
        {
            "rankedAuthorities": [
                "LIVE_TV_SPORTS_TEAM_ER_SERVICE",
                "LIVE_SPORTS_ER_SERVICE"
            ]

tolinwei

import java.util.*;

public class Main {
    public static void main(String args[])
    {
        Map<Integer, Integer> map = new HashMap();
        map.put(1, 3);
        map.put(2, 4);
        map.put(5, 7);