結果

問題 No.364 門松木
ユーザー uwiuwi
提出日時 2016-03-24 04:22:55
言語 Java21
(openjdk 21)
結果
AC  
実行時間 714 ms / 3,000 ms
コード長 6,815 bytes
コンパイル時間 3,759 ms
コンパイル使用メモリ 87,220 KB
実行使用メモリ 50,028 KB
最終ジャッジ日時 2024-10-01 21:50:10
合計ジャッジ時間 17,956 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge2
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 52 ms
36,980 KB
testcase_01 AC 53 ms
37,232 KB
testcase_02 AC 52 ms
37,232 KB
testcase_03 AC 55 ms
37,112 KB
testcase_04 AC 53 ms
37,380 KB
testcase_05 AC 53 ms
37,108 KB
testcase_06 AC 53 ms
37,192 KB
testcase_07 AC 50 ms
37,028 KB
testcase_08 AC 476 ms
49,460 KB
testcase_09 AC 422 ms
49,440 KB
testcase_10 AC 489 ms
49,968 KB
testcase_11 AC 583 ms
49,832 KB
testcase_12 AC 453 ms
49,956 KB
testcase_13 AC 499 ms
49,884 KB
testcase_14 AC 461 ms
49,676 KB
testcase_15 AC 488 ms
49,788 KB
testcase_16 AC 465 ms
49,476 KB
testcase_17 AC 595 ms
49,564 KB
testcase_18 AC 482 ms
49,340 KB
testcase_19 AC 581 ms
49,876 KB
testcase_20 AC 474 ms
49,376 KB
testcase_21 AC 557 ms
49,276 KB
testcase_22 AC 506 ms
48,440 KB
testcase_23 AC 526 ms
49,808 KB
testcase_24 AC 580 ms
49,620 KB
testcase_25 AC 553 ms
49,648 KB
testcase_26 AC 530 ms
49,664 KB
testcase_27 AC 536 ms
49,760 KB
testcase_28 AC 714 ms
50,028 KB
testcase_29 AC 552 ms
49,488 KB
testcase_30 AC 468 ms
49,824 KB
testcase_31 AC 51 ms
36,872 KB
testcase_32 AC 53 ms
37,064 KB
testcase_33 AC 432 ms
49,408 KB
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ソースコード

diff # 

package contest;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class Q1009 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		if(!(n >= 1))throw new AssertionError();
		if(!(n <= 50000))throw new AssertionError();
		int[] a = na(n);
		for(int v : a){
			if(!(v >= 1))throw new AssertionError();
			if(!(v <= 1000))throw new AssertionError();
		}
		int[] from = new int[n - 1];
		int[] to = new int[n - 1];
		DJSet ds = new DJSet(n);
		for (int i = 0; i < n - 1; i++) {
			from[i] = ni() - 1;
			to[i] = ni() - 1;
			if(!(from[i] >= 0))throw new AssertionError();
			if(!(from[i] < n))throw new AssertionError();
			if(!(to[i] >= 0))throw new AssertionError();
			if(!(to[i] < n))throw new AssertionError();
			if(!(to[i] != from[i]))throw new AssertionError();
			ds.union(from[i], to[i]);
		}
		if(!(ds.count() == 1))throw new AssertionError();
		int[][] g = packU(n, from, to);
		int[][] pars = parents3(g, 0);
		int[] par = pars[0], ord = pars[1], dep = pars[2];
		
		int Z = 1001;
		// 1個上の親に遠慮した最高スコア
		long[] big = new long[n];
		long[] small = new long[n];
		long ret = 0;
		for(int i = n-1;i >= 0;i--){
			int cur = ord[i];
			// curがbig
			{
				long[] valscores = new long[Z];
				Arrays.fill(valscores, -1);
				for(int e : g[cur]){
					if(par[cur] != e && a[e] < a[cur]){
						valscores[a[e]] = Math.max(valscores[a[e]], small[e]);
					}
				}
				
				long score = 0;
				long hand = 0;
				for(long v : valscores){
					if(v >= 0){
						hand++;
						score += v;
					}
				}
				// curがrootの場合のスコア
				ret = Math.max(ret, score+hand*(hand-1)/2);
				
				if(par[cur] != -1 && a[cur] > a[par[cur]]){
					if(valscores[a[par[cur]]] != -1){
						// 親と同じ値をのぞいて親を選ぶ
						score -= valscores[a[par[cur]]];
					}else{
						// 親をただ選ぶ
						hand++;
					}
					big[cur] = score + hand*(hand-1)/2;
				}
			}
			
			// curがsmall
			{
				long[] valscores = new long[Z];
				Arrays.fill(valscores, -1);
				for(int e : g[cur]){
					if(par[cur] != e && a[e] > a[cur]){
						valscores[a[e]] = Math.max(valscores[a[e]], big[e]);
					}
				}
				
				long score = 0;
				long hand = 0;
				for(long v : valscores){
					if(v >= 0){
						hand++;
						score += v;
					}
				}
				// curがrootの場合のスコア
				ret = Math.max(ret, score+hand*(hand-1)/2);
				
				if(par[cur] != -1 && a[cur] < a[par[cur]]){
					if(valscores[a[par[cur]]] != -1){
						// 親と同じ値をのぞいて親を選ぶ
						score -= valscores[a[par[cur]]];
					}else{
						// 親をただ選ぶ
						hand++;
					}
					small[cur] = score + hand*(hand-1)/2;
				}
			}
		}
		out.println(ret);
	}
	
	public static class DJSet {
		public int[] upper;

		public DJSet(int n) {
			upper = new int[n];
			Arrays.fill(upper, -1);
		}

		public int root(int x) {
			return upper[x] < 0 ? x : (upper[x] = root(upper[x]));
		}

		public boolean equiv(int x, int y) {
			return root(x) == root(y);
		}

		public boolean union(int x, int y) {
			x = root(x);
			y = root(y);
			if (x != y) {
				if (upper[y] < upper[x]) {
					int d = x;
					x = y;
					y = d;
				}
				upper[x] += upper[y];
				upper[y] = x;
			}
			return x == y;
		}

		public int count() {
			int ct = 0;
			for (int u : upper)
				if (u < 0)
					ct++;
			return ct;
		}
	}
	
	public static int[][] parents3(int[][] g, int root) {
		int n = g.length;
		int[] par = new int[n];
		Arrays.fill(par, -1);
	
		int[] depth = new int[n];
		depth[0] = 0;
	
		int[] q = new int[n];
		q[0] = root;
		for (int p = 0, r = 1; p < r; p++) {
			int cur = q[p];
			for (int nex : g[cur]) {
				if (par[cur] != nex) {
					q[r++] = nex;
					par[nex] = cur;
					depth[nex] = depth[cur] + 1;
				}
			}
		}
		return new int[][] { par, q, depth };
	}
	
	static int[][] packU(int n, int[] from, int[] to) {
		int[][] g = new int[n][];
		int[] p = new int[n];
		for (int f : from)
			p[f]++;
		for (int t : to)
			p[t]++;
		for (int i = 0; i < n; i++)
			g[i] = new int[p[i]];
		for (int i = 0; i < from.length; i++) {
			g[from[i]][--p[from[i]]] = to[i];
			g[to[i]][--p[to[i]]] = from[i];
		}
		return g;
	}

	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
	}
	
	public static void main(String[] args) throws Exception { new Q1009().run(); }
	
	private byte[] inbuf = new byte[1024];
	private int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}
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