shixiaoyu

public class Block {
    public int x;
    public int y;

    public Block(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

shixiaoyu

// This is a DFS solution, basically just like detecting if a graph has loops.
// Used a lookup table prune, with lookup, this is O(V + E), same as BFS since each node is visited once and only once
public boolean canFinish(int numCourses, int[][] prerequisites) {
    if (numCourses <= 1 || prerequisites.length == 0 || prerequisites[0].length == 0) {
        return true;
    }

    // this is adjacency list, used a set to dedup
    Map<Integer, Set<Integer>> graph = new HashMap<>();

shixiaoyu

public boolean canFinishBfsTopoSort(int numCourses, int[][] prerequisites) {
    if (numCourses <= 1 || prerequisites.length == 0 || prerequisites[0].length == 0) {
        return true;
    }

    Map<Integer, Set<Integer>> graph = new HashMap<>();

    // could be extracted into a build graph function
    for (int i = 0; i < numCourses; i++) {
        graph.put(i, new HashSet<>());

shixiaoyu

private class Node {
    public int val;
    public List<Node> neighbors;

    public Node(int val) {
        this.val = val;
        this.neighbors = new ArrayList<>();
    }
}

shixiaoyu

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

public class Solution {
    public static void main(String[] args) {
        Scanner s = new Scanner(new BufferedReader(new InputStreamReader(System.in)));

        int testCases = s.nextInt();
        int caseNum = 1;

shixiaoyu

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.Stack;

public class Solution {
    public static void main(String[] args) {
        Scanner s = new Scanner(new BufferedReader(new InputStreamReader(System.in)));

        int testCases = s.nextInt();

shixiaoyu

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        Scanner s = new Scanner(new BufferedReader(new InputStreamReader(System.in)));

        int testCases = s.nextInt();

shixiaoyu

public static void main(String[] args) {
    Scanner s = new Scanner(new BufferedReader(new InputStreamReader(System.in)));

    int testCases = s.nextInt();
    int caseNum = 1;
    Training training = new Training();

    while (caseNum <= testCases) {
        int n = s.nextInt();
        int p = s.nextInt();

shixiaoyu

public static void main(String[] args) {
    Scanner s = new Scanner(new BufferedReader(new InputStreamReader(System.in)));

    int testCases = s.nextInt();
    int caseNum = 1;
    Plates plates = new Plates();

    while (caseNum <= testCases) {
        int n = s.nextInt();
        int k = s.nextInt();

shixiaoyu

public void sortColors(int[] A) {
    if (A == null || A.length == 0) return;

    int left = 0;
    int right = A.length - 1;

    int i = 0; 
    while (i <= right) { // has to be <=, since cur value still needs to be evaluated if swapped back
        if (A[i] == 1) {
            i++;