結果

問題 No.1031 いたずら好きなお姉ちゃん
ユーザー uwiuwi
提出日時 2020-04-18 16:47:28
言語 Java21
(openjdk 21)
結果
AC  
実行時間 420 ms / 3,500 ms
コード長 7,132 bytes
コンパイル時間 3,883 ms
コンパイル使用メモリ 83,500 KB
実行使用メモリ 71,496 KB
最終ジャッジ日時 2024-10-03 23:58:06
合計ジャッジ時間 20,925 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge1
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 46 ms
37,048 KB
testcase_01 AC 46 ms
37,008 KB
testcase_02 AC 47 ms
37,056 KB
testcase_03 AC 73 ms
38,868 KB
testcase_04 AC 71 ms
39,048 KB
testcase_05 AC 72 ms
39,056 KB
testcase_06 AC 72 ms
39,004 KB
testcase_07 AC 72 ms
39,016 KB
testcase_08 AC 71 ms
38,980 KB
testcase_09 AC 63 ms
38,772 KB
testcase_10 AC 70 ms
38,616 KB
testcase_11 AC 310 ms
67,656 KB
testcase_12 AC 290 ms
65,400 KB
testcase_13 AC 326 ms
67,252 KB
testcase_14 AC 345 ms
67,152 KB
testcase_15 AC 313 ms
67,312 KB
testcase_16 AC 265 ms
69,748 KB
testcase_17 AC 379 ms
66,584 KB
testcase_18 AC 295 ms
69,680 KB
testcase_19 AC 297 ms
66,968 KB
testcase_20 AC 357 ms
66,052 KB
testcase_21 AC 341 ms
66,212 KB
testcase_22 AC 318 ms
66,292 KB
testcase_23 AC 277 ms
70,380 KB
testcase_24 AC 345 ms
65,704 KB
testcase_25 AC 413 ms
67,172 KB
testcase_26 AC 391 ms
69,520 KB
testcase_27 AC 310 ms
69,316 KB
testcase_28 AC 311 ms
65,784 KB
testcase_29 AC 342 ms
67,524 KB
testcase_30 AC 364 ms
65,552 KB
testcase_31 AC 347 ms
66,808 KB
testcase_32 AC 352 ms
65,584 KB
testcase_33 AC 420 ms
68,200 KB
testcase_34 AC 281 ms
59,708 KB
testcase_35 AC 293 ms
71,380 KB
testcase_36 AC 296 ms
68,532 KB
testcase_37 AC 307 ms
71,496 KB
testcase_38 AC 374 ms
67,104 KB
testcase_39 AC 269 ms
64,620 KB
testcase_40 AC 276 ms
66,036 KB
testcase_41 AC 339 ms
68,128 KB
testcase_42 AC 327 ms
64,392 KB
testcase_43 AC 372 ms
67,080 KB
testcase_44 AC 277 ms
65,884 KB
testcase_45 AC 348 ms
66,864 KB
testcase_46 AC 275 ms
66,100 KB
testcase_47 AC 266 ms
65,976 KB
testcase_48 AC 290 ms
68,864 KB
testcase_49 AC 290 ms
67,396 KB
testcase_50 AC 304 ms
68,464 KB
testcase_51 AC 336 ms
64,860 KB
testcase_52 AC 333 ms
65,408 KB
testcase_53 AC 295 ms
65,048 KB
testcase_54 AC 47 ms
36,868 KB
testcase_55 AC 47 ms
36,864 KB
権限があれば一括ダウンロードができます

ソースコード

diff # 

package contest200417;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

// O(n)
public class E3 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		int[] a = na(n);
		
		out.println(go(a) + go(rev(a)));
	}
	
	public static int[] rev(int[] a){int[] b = new int[a.length];for(int i = 0;i < a.length;i++)b[a.length-1-i] = a[i];return b;}

	
	long go(int[] a)
	{		
		int n = a.length;
		int[] larger = enumPrevWall(a);
		int[] smaller = enumPrevShutter(a);
		int[] par = new int[n+1];
		for(int i = 0;i < n;i++){
			par[i] = larger[i] == -1 ? n : larger[i];
		}
		par[n] = -1;
		int[][] g = parentToG(par);
		
		int[][] pars = parents3(g, n);
		int[] dep = pars[2];
		
		int[][] qs = new int[n][];
		
		long ans = 0;
		int p = 0;
		for(int i = 0;i < n;i++){
			int s = smaller[i];
			if(s != -1)qs[p++] = new int[]{i, smaller[i], -1};
			
			ans += dep[i];
		}
		ans -= n;
		int[] rets = offlineLCA(g, Arrays.copyOf(qs, p), n);
		for(int i = 0;i < p;i++){
			ans -= dep[rets[i]];
		}
		
		return ans;
	}
	
	public static int[] offlineLCA(int[][] g, int[][] qs, int root)
	{
		int n = g.length;
		DJSet ds = new DJSet(n);
		int[] ancs = new int[n];
		for(int i = 0;i < n;i++)ancs[i] = i;
		int Q = qs.length;
		long[][] qg = packUInd(n, qs);
		boolean[] ved = new boolean[n];
		int[] rets = new int[Q];
		Arrays.fill(rets, -1);
		int[] stack = new int[n+1];
		int[] inds = new int[n+1];
		int sp = 0;
		stack[sp++] = root;
		while(sp > 0){
			int cur = stack[sp-1];
			if(inds[sp-1] < g[cur].length){
				int e = g[cur][inds[sp-1]];
				if(sp-2 >= 0 && stack[sp-2] == e){
					inds[sp-1]++;
				}else if(ved[e]){
					ds.union(cur, e);
					ancs[ds.root(cur)] = cur;
					inds[sp-1]++;
				}else{
					inds[sp] = 0;
					stack[sp++] = e;
				}
			}else{
				ved[cur] = true;
				for(long q : qg[cur]){
					if(ved[(int)(q>>>32)]){
						rets[(int)q] = ancs[ds.root((int)(q>>>32))];
					}
				}
				sp--;
			}
		}
		return rets;
	}
	
	public static long[][] packUInd(int n, int[][] ft)
	{
		long[][] g = new long[n][];
		int[] p = new int[n];
		for(int[] u : ft){
			p[u[0]]++; p[u[1]]++;
		}
		for(int i = 0;i < n;i++)g[i] = new long[p[i]];
		int id = 0;
		for(int[] u : ft){
			g[u[0]][--p[u[0]]] = (long)u[1]<<32|id;
			g[u[1]][--p[u[1]]] = (long)u[0]<<32|id;
			id++;
		}
		return g;
	}
	
	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 };
	}

	
	public static int[][] parentToG(int[] par)
	{
		int n = par.length;
		int[] ct = new int[n];
		for(int i = 0;i < n;i++){
			if(par[i] >= 0){
				ct[i]++;
				ct[par[i]]++;
			}
		}
		int[][] g = new int[n][];
		for(int i = 0;i < n;i++){
			g[i] = new int[ct[i]];
		}
		for(int i = 0;i < n;i++){
			if(par[i] >= 0){
				g[par[i]][--ct[par[i]]] = i;
				g[i][--ct[i]] = par[i];
			}
		}
		return g;
	}
	

	
	
	
	public static int[] enumPrevWall(int[] a)
	{
		int n = a.length;
		int[] L = new int[n];
		L[0] = -1;
		for(int i = 1;i < n;i++){
			L[i] = i-1;
			while(L[i] >= 0 && a[L[i]] < a[i])L[i] = L[L[i]];
		}
		return L;
	}

	public static int[] enumPrevShutter(int[] a)
	{
		int n = a.length;
		int[] L = new int[n];
		L[0] = -1;
		for(int i = 1;i < n;i++){
			L[i] = i-1;
			while(L[i] >= 0 && a[L[i]] > a[i])L[i] = L[L[i]];
		}
		return L;
	}

	
	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");
//		Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
//			@Override
//			public void run() {
//				long s = System.currentTimeMillis();
//				solve();
//				out.flush();
//				if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
//			}
//		};
//		t.start();
//		t.join();
	}
	
	public static void main(String[] args) throws Exception { new E3().run(); }
	
	private byte[] inbuf = new byte[1024];
	public 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 int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private long[] nal(int n)
	{
		long[] a = new long[n];
		for(int i = 0;i < n;i++)a[i] = nl();
		return a;
	}
	
	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[][] nmi(int n, int m) {
		int[][] map = new int[n][];
		for(int i = 0;i < n;i++)map[i] = na(m);
		return map;
	}
	
	private int ni() { return (int)nl(); }
	
	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)); }
}
0