Problem:
Score : 500 points

Problem Statement

There is an infinitely long street that runs west to east, which we consider as a number line.

There are N roadworks scheduled on this street.
The i-th roadwork blocks the point at coordinate X_i from time S_i - 0.5 to time T_i - 0.5.

Q people are standing at coordinate 0. The i-th person will start the coordinate 0 at time D_i, continue to walk with speed 1 in the positive direction and stop walking when reaching a blocked point.

Find the distance each of the Q people will walk.

Constraints

All values in input are integers.

1 \leq N, Q \leq 2 \times 10^5

0 \leq S_i < T_i \leq 10^9

1 \leq X_i \leq 10^9

0 \leq D_1 < D_2 < ... < D_Q \leq 10^9

If i \neq j and X_i = X_j, the intervals [S_i, T_i) and [S_j, T_j) do not overlap.

Input

Input is given from Standard Input in the following format:

N Q
S_1 T_1 X_1
:
S_N T_N X_N
D_1
:
D_Q

Output

Print Q lines. The i-th line should contain the distance the i-th person will walk or -1 if that person walks forever.

Sample Input 1

4 6
1 3 2
7 13 10
18 20 13
3 4 2
0
1
2
3
5
8

Sample Output 1

2
2
10
-1
13
-1

The first person starts coordinate 0 at time 0 and stops walking at coordinate 2 when reaching a point blocked by the first roadwork at time 2.

The second person starts coordinate 0 at time 1 and reaches coordinate 2 at time 3. The first roadwork has ended, but the fourth roadwork has begun, so this person also stops walking at coordinate 2.

The fourth and sixth persons encounter no roadworks while walking, so they walk forever. The output for these cases is -1.

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Threading.Tasks;

namespace AtCorder
{
	public class Program
	{
		static void Main(string[] args)
		{
			var cin = new Scanner2();
			int n = cin.Int();
			int q = cin.Int();
			var stx = new STX[n];
			for (int i = 0; i < n; i++) {
				long s = cin.Long();
				long t = cin.Long();
				long x = cin.Long();
				stx[i] = new STX { S = s - x, T = t - x, X = x};
			}

			long[] d = new long[q];
			for (int i = 0; i < q; i++) {
				d[i] = cin.Long();
			}

			var start = new List<long>[q];
			var end = new List<long>[q];
			for (int i = 0; i < q; i++) {
				start[i] = new List<long>();
				end[i] = new List<long>();
			}

			for (int i = 0; i < n; i++) {
				int si = LowerBound(d, stx[i].S);
				int ti = LowerBound(d, stx[i].T) - 1;
				if (ti < 0) {
					continue;
				}

				si = Math.Max(0, si);
				ti = Math.Max(0, ti);

				if (si < q) {
					start[si].Add(stx[i].X);
				}

				if (ti < q) {
					end[ti].Add(stx[i].X);
				}
			}

			var sb = new StringBuilder();
			var set = new MultiSet<long>(q);
			for (int i = 0; i < q; i++) {
				foreach (long val in start[i]) {
					set.Add(val);
				}

				if (set.Count > 0) {
					sb.AppendLine(set.Min.ToString());
				} else {
					sb.AppendLine("-1");
				}

				foreach (long val in end[i]) {
					set.Remove(val);
				}
			}

			Console.WriteLine(sb.ToString());
		}

		public static int LowerBound(IReadOnlyList<long> list, long target)
		{
			int left = -1;
			int right = list.Count();

			while (right - left > 1) {
				int mid = (right + left) / 2;
				if (list[mid] >= target) {
					right = mid;
				} else {
					left = mid;
				}
			}

			return right;
		}

		public static int UpperBound(IReadOnlyList<long> list, long target)
		{
			int left = -1;
			int right = list.Count();

			while (right - left > 1) {
				int mid = (right + left) / 2;
				if (list[mid] > target) {
					right = mid;
				} else {
					left = mid;
				}
			}

			return right;
		}
	}

	public struct STX
	{
		public long S { get; set; }
		public long T { get; set; }

		public long X { get; set; }
	}

	public class MultiSet<T> :
		IEnumerable<T>,
		System.Collections.IEnumerable,
		ICollection<T>,
		System.Collections.ICollection,
		IReadOnlyCollection<T>
	{
		private readonly SortedSet<T> set_;
		private readonly Dictionary<T, int> counts_ = new Dictionary<T, int>();

		public MultiSet(
			int capacity,
			IEnumerable<T> collection = null,
			IComparer<T> comparer = null)
		{
			counts_ = new Dictionary<T, int>(capacity);
			if (collection == null && comparer == null) {
				set_ = new SortedSet<T>();
			} else if (collection == null) {
				set_ = new SortedSet<T>(comparer);
			} else if (comparer == null) {
				set_ = new SortedSet<T>(collection);
			} else {
				set_ = new SortedSet<T>(collection, comparer);
			}
		}

		public IComparer<T> Comparer => set_.Comparer;
		public int Count { get; private set; }
		public T Max => set_.Max;
		public T Min => set_.Min;

		public bool IsReadOnly => false;

		object System.Collections.ICollection.SyncRoot
			=> (set_ as System.Collections.ICollection).SyncRoot;

		bool System.Collections.ICollection.IsSynchronized
			=> (set_ as System.Collections.ICollection).IsSynchronized;

		public bool Add(T item)
		{
			if (counts_.ContainsKey(item) == false) {
				counts_[item] = 1;
			} else {
				counts_[item]++;
			}

			set_.Add(item);
			++Count;
			return true;
		}

		public bool Remove(T item)
		{
			if (counts_.ContainsKey(item) == false) {
				return false;
			}

			counts_[item]--;
			Count--;
			if (counts_[item] == 0) {
				counts_.Remove(item);
				set_.Remove(item);
			}

			return true;
		}

		public void Clear()
		{
			counts_.Clear();
			Count = 0;
			set_.Clear();
		}

		public bool Contains(T item) => set_.Contains(item);

		public IEnumerator<T> GetEnumerator()
		{
			foreach (var s in set_) {
				for (int i = 0; i < counts_[s]; i++) {
					yield return s;
				}
			}
		}

		System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
			=> GetEnumerator();

		void ICollection<T>.Add(T item) => Add(item);

		public void CopyTo(T[] array, int arrayIndex)
		{
			int index = arrayIndex;
			foreach (var s in set_) {
				for (int i = 0; i < counts_[s]; i++) {
					array[index] = s;
					++index;
				}
			}
		}

		void System.Collections.ICollection.CopyTo(Array array, int index)
		{
		}
	}

	public class Scanner2
	{
		private readonly char[] delimiter_ = new char[] { ' ' };
		private readonly string filePath_;
		private readonly Func<string> reader_;
		private string[] buf_;
		private int index_;

		public Scanner2(string file = "")
		{
			if (string.IsNullOrWhiteSpace(file)) {
				reader_ = Console.ReadLine;
			} else {
				filePath_ = file;
				var fs = new StreamReader(file);
				reader_ = fs.ReadLine;
			}
			buf_ = new string[0];
			index_ = 0;
		}

		public string Next()
		{
			if (index_ < buf_.Length) {
				return buf_[index_++];
			}

			string st = reader_();
			while (st == "") {
				st = reader_();
			}

			buf_ = st.Split(delimiter_, StringSplitOptions.RemoveEmptyEntries);
			if (buf_.Length == 0) {
				return Next();
			}

			index_ = 0;
			return buf_[index_++];
		}

		public int Int() => int.Parse(Next());
		public long Long() => long.Parse(Next());
		public double Double() => double.Parse(Next());

		public int[] ArrayInt(int N, int add = 0)
		{
			int[] Array = new int[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Int() + add;
			}
			return Array;
		}

		public long[] ArrayLong(int N, long add = 0)
		{
			long[] Array = new long[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Long() + add;
			}
			return Array;
		}

		public double[] ArrayDouble(int N, double add = 0)
		{
			double[] Array = new double[N];
			for (int i = 0; i < N; i++) {
				Array[i] = Double() + add;
			}
			return Array;
		}

		public void Save(string text)
		{
			if (string.IsNullOrWhiteSpace(filePath_)) {
				return;
			}

			File.WriteAllText(filePath_ + "_output.txt", text);
		}
	}
}