Submission #274571

#	Time	Username	Problem	Language	Result	Execution time	Memory
274571		Gilgamesh	Collecting Stamps 3 (JOI20_ho_t3)	Java	15 / 100	2597 ms	123184 KiB

ho_t3

import java.util.*;
import java.io.*;

public class ho_t3 {
	final static int MOD = 1000000007;
	final static int intMax = 1000000000;
	final static int intMin = -1000000000;
	final static int[] dx = { 0, 0, -1, 1 };
	final static int[] dy = { -1, 1, 0, 0 };

	static int T;

	static class Reader {
		final private int BUFFER_SIZE = 1 << 16;
		private DataInputStream din;
		private byte[] buffer;
		private int bufferPointer, bytesRead;

		public Reader() {
			din = new DataInputStream(System.in);
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public Reader(String file_name) throws IOException {
			din = new DataInputStream(new FileInputStream(file_name));
			buffer = new byte[BUFFER_SIZE];
			bufferPointer = bytesRead = 0;
		}

		public String readLine() throws IOException {
			byte[] buf = new byte[360]; // line length
			int cnt = 0, c;
			while ((c = read()) != -1) {
				if (c == '\n')
					break;
				buf[cnt++] = (byte) c;
			}
			return new String(buf, 0, cnt);
		}

		public int nextInt() throws IOException {
			int ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');

			if (neg)
				return -ret;
			return ret;
		}

		public long nextLong() throws IOException {
			long ret = 0;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();
			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');
			if (neg)
				return -ret;
			return ret;
		}

		public double nextDouble() throws IOException {
			double ret = 0, div = 1;
			byte c = read();
			while (c <= ' ')
				c = read();
			boolean neg = (c == '-');
			if (neg)
				c = read();

			do {
				ret = ret * 10 + c - '0';
			} while ((c = read()) >= '0' && c <= '9');

			if (c == '.') {
				while ((c = read()) >= '0' && c <= '9') {
					ret += (c - '0') / (div *= 10);
				}
			}

			if (neg)
				return -ret;
			return ret;
		}

		private void fillBuffer() throws IOException {
			bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
			if (bytesRead == -1)
				buffer[0] = -1;
		}

		private byte read() throws IOException {
			if (bufferPointer == bytesRead)
				fillBuffer();
			return buffer[bufferPointer++];
		}

		public void close() throws IOException {
			if (din == null)
				return;
			din.close();
		}
	}
	
	static long min(long a, long b) {
		return a < b ? a : b;
	}
	
	public static void main(String[] args) throws Exception {
		Reader in = new Reader();
		int N = in.nextInt();
		int L = in.nextInt();
		int[] X = new int[N + 1];
		int[] X2 = new int[N + 1];
		int[] T = new int[N];
		for(int i = 1; i <= N; ++i) {
			X[i] = in.nextInt();
		}
		for(int i = 0; i < N; ++i) {
			T[i] = in.nextInt();
		}
		for(int i = N; i >= 1; --i) {
			X2[N - i + 1] = L - X[i];
		}
		long[][][][] dp = new long[N + 1][N + 1][N + 1][2]; //dp[i][j][k][l] = min time to i stamps, j left, k right, l = 0 last left, 1 last right
		for(int i = 0; i <= N; ++i) {
			for(int j = 0; j <= N; ++j) {
				for(int k = 0; k <= N; ++k) {
					dp[i][j][k][0] = Long.MAX_VALUE / 2;
					dp[i][j][k][1] = Long.MAX_VALUE / 2;
				}
			}
		}
		dp[0][0][0][0] = 0;
		dp[0][0][0][1] = 0;
		int ans = 0;
		for(int i = 0; i <= N; ++i) {
			for(int j = 0; j <= N; ++j) {
				for(int k = 0; k <= N; ++k) {
					if(j + k > N || j + k < i) continue;
					if(j > 0) {
						//transition from dp[i - 1][j - 1][k][0], dp[i - 1][j - 1][k][1], dp[i][j - 1][k][0], dp[i][j - 1][k][1]
						dp[i][j][k][0] = dp[i][j - 1][k][0] + X2[j] - X2[j - 1];
						if(i > 0 && dp[i - 1][j - 1][k][0] + X2[j] - X2[j - 1] <= T[N - j]) 
							dp[i][j][k][0] = min(dp[i][j][k][0], dp[i - 1][j - 1][k][0] + X2[j] - X2[j - 1]);
						dp[i][j][k][0] = min(dp[i][j][k][0], dp[i][j - 1][k][1] + X2[j] + X[k]);
						if(i > 0 && dp[i - 1][j - 1][k][1] + X2[j] + X[k] <= T[N - j])
							dp[i][j][k][0] = min(dp[i][j][k][0], dp[i - 1][j - 1][k][1] + X2[j] + X[k]);
					}
					if(k > 0) {
						dp[i][j][k][1] = dp[i][j][k - 1][0] + X2[j] + X[k];
						if(i > 0 && dp[i - 1][j][k - 1][0] + X2[j] + X[k] <= T[k - 1])
							dp[i][j][k][1] = min(dp[i][j][k][1], dp[i - 1][j][k - 1][0] + X2[j] + X[k]);
						dp[i][j][k][1] = min(dp[i][j][k][1], dp[i][j][k - 1][1] + X[k] - X[k - 1]);
						if(i > 0 && dp[i - 1][j][k - 1][1] + X[k] - X[k - 1] <= T[k - 1])
							dp[i][j][k][1] = min(dp[i][j][k][1], dp[i - 1][j][k - 1][1] + X[k] - X[k - 1]);
					}
					if(dp[i][j][k][0] < Long.MAX_VALUE / 2 || dp[i][j][k][1] < Long.MAX_VALUE / 2) ans = i;
				}
			}
		}
		System.out.println(ans);
		in.close();
	}
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75