#516681 (Java21) No.1124 Earthquake Safety

提出ソース

結果

問題	No.1124 Earthquake Safety
ユーザー	uwi
提出日時	2020-07-22 23:17:34
言語	Java21 (openjdk 21)
結果	AC
実行時間	715 ms / 3,000 ms
コード長	7,675 bytes
コンパイル時間	4,585 ms
コンパイル使用メモリ	88,628 KB
実行使用メモリ	110,628 KB
最終ジャッジ日時	2024-06-23 01:01:46
合計ジャッジ時間	34,837 ms
ジャッジサーバーID （参考情報）	judge4 / judge3

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	48 ms 36,864 KB
testcase_01	AC	45 ms 36,740 KB
testcase_02	AC	46 ms 36,580 KB
testcase_03	AC	44 ms 36,880 KB
testcase_04	AC	45 ms 36,808 KB
testcase_05	AC	46 ms 36,516 KB
testcase_06	AC	48 ms 37,480 KB
testcase_07	AC	76 ms 42,720 KB
testcase_08	AC	314 ms 58,896 KB
testcase_09	AC	629 ms 88,164 KB
testcase_10	AC	532 ms 87,520 KB
testcase_11	AC	43 ms 36,824 KB
testcase_12	AC	45 ms 38,120 KB
testcase_13	AC	43 ms 36,932 KB
testcase_14	AC	715 ms 102,524 KB
testcase_15	AC	704 ms 88,416 KB
testcase_16	AC	634 ms 88,168 KB
testcase_17	AC	698 ms 90,256 KB
testcase_18	AC	661 ms 88,164 KB
testcase_19	AC	653 ms 102,644 KB
testcase_20	AC	656 ms 90,316 KB
testcase_21	AC	689 ms 88,664 KB
testcase_22	AC	694 ms 98,388 KB
testcase_23	AC	632 ms 87,504 KB
testcase_24	AC	640 ms 89,204 KB
testcase_25	AC	650 ms 99,148 KB
testcase_26	AC	601 ms 87,304 KB
testcase_27	AC	621 ms 87,488 KB
testcase_28	AC	619 ms 97,224 KB
testcase_29	AC	621 ms 89,368 KB
testcase_30	AC	649 ms 100,324 KB
testcase_31	AC	638 ms 97,012 KB
testcase_32	AC	627 ms 88,596 KB
testcase_33	AC	608 ms 92,004 KB
testcase_34	AC	606 ms 86,316 KB
testcase_35	AC	668 ms 91,476 KB
testcase_36	AC	701 ms 90,012 KB
testcase_37	AC	681 ms 90,876 KB
testcase_38	AC	671 ms 90,100 KB
testcase_39	AC	646 ms 90,684 KB
testcase_40	AC	657 ms 100,128 KB
testcase_41	AC	625 ms 99,968 KB
testcase_42	AC	632 ms 97,364 KB
testcase_43	AC	642 ms 97,568 KB
testcase_44	AC	690 ms 99,404 KB
testcase_45	AC	595 ms 90,228 KB
testcase_46	AC	628 ms 98,392 KB
testcase_47	AC	660 ms 99,480 KB
testcase_48	AC	683 ms 110,628 KB
testcase_49	AC	684 ms 103,816 KB
testcase_50	AC	44 ms 38,284 KB
testcase_51	AC	43 ms 36,508 KB
testcase_52	AC	44 ms 37,080 KB
testcase_53	AC	44 ms 36,824 KB
testcase_54	AC	44 ms 36,764 KB
testcase_55	AC	43 ms 36,820 KB
testcase_56	AC	46 ms 36,460 KB
testcase_57	AC	45 ms 36,640 KB

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ソースコード

raw source code

package contest200722;
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 F {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		int[] from = new int[n - 1];
		int[] to = new int[n - 1];
		for (int i = 0; i < n - 1; i++) {
			from[i] = ni() - 1;
			to[i] = ni() - 1;
		}
		int[][] g = packU(n, from, to);
		int[][] pars = parents3(g, 0);
		int[] par = pars[0], ord = pars[1], dep = pars[2];
		
		Datum[] res = omnidirectionalTreeDP(g, par, ord);
		
		long ans = 0;
		long px = pow(2, n-1, mod);
		for(Datum v : res){
			ans += 2*v.v + v.d;
		}
		out.println(ans%mod*px%mod);
	}
	
	public static class Datum
	{
		long v;
		long d;
		
		public Datum()
		{
			v = 0;
			d = 0;
		}
		
		public Datum(int cur)
		{
			v = 0;
			d = 1;
		}

		@Override
		public String toString() {
			return "Datum [v=" + v + ", d=" + d + "]";
		}
	}
	
	public static Datum zero = new Datum();
	
	public static Datum merge(Datum a, Datum b)
	{
		Datum ret = new Datum();
		ret.v = (a.v + b.v + a.d * b.d) % mod;
		ret.d = (a.d + b.d) % mod;
		return ret;
	}
	
	public static Datum promote(Datum d, int... e)
	{
		Datum ret = new Datum();
		ret.d = d.d * i2 % mod;
		ret.v = d.v * i2 % mod;
		return ret;
	}
	
	
	public static Datum[] omnidirectionalTreeDP(int[][] g, int[] par, int[] ord) {
		int n = g.length;
		int root = ord[0];
		
		Datum[] dp = new Datum[n];
		
		// up
		for(int i = n-1;i >= 0;i--){
			int cur = ord[i];
			Datum ldp = new Datum(cur);
			for(int e : g[cur]){
				if(par[cur] == e)continue;
				ldp = merge(ldp, promote(dp[e], e));
			}
			dp[cur] = ldp;
		}
		
		// down
		Datum[] prefix = new Datum[n+1];
		Datum[] fall = new Datum[n];
		fall[root] = zero;
		for(int i = 0;i < n;i++){
			int cur = ord[i];
			prefix[0] = zero;
			Datum suffix = merge(new Datum(cur), fall[cur]);
			for(int j = 0;j < g[cur].length;j++){
				int e = g[cur][j];
				prefix[j+1] = par[cur] == e ? prefix[j] : merge(prefix[j], promote(dp[e], e));
			}
			for(int j = 0;j < g[cur].length;j++){
				int e = g[cur][g[cur].length-1-j];
				if(par[cur] != e){
					fall[e] = promote(merge(prefix[g[cur].length-1-j], suffix), e);
				}
				suffix = par[cur] == e ? suffix : merge(suffix, promote(dp[e], e));
			}
		}
		
		for(int i = 0;i < n;i++){
			dp[i] = merge(fall[i], dp[i]);
		}
		return dp;
	}
	
	
	public static Datum[] omnidirectionalTreeDP(int[][][] g, int[] par, int[] ord) {
		int n = g.length;
		int root = ord[0];
		
		Datum[] dp = new Datum[n];
		
		// up
		for(int i = n-1;i >= 0;i--){
			int cur = ord[i];
			Datum ldp = new Datum(cur);
			for(int[] e : g[cur]){
				if(par[cur] == e[0])continue;
				ldp = merge(ldp, promote(dp[e[0]], e));
			}
			dp[cur] = ldp;
		}
		
		// down
		Datum[] prefix = new Datum[n+1];
		Datum[] fall = new Datum[n];
		fall[root] = zero;
		for(int i = 0;i < n;i++){
			int cur = ord[i];
			prefix[0] = zero;
			Datum suffix = merge(new Datum(cur), fall[cur]);
			for(int j = 0;j < g[cur].length;j++){
				int[] e = g[cur][j];
				prefix[j+1] = par[cur] == e[0] ? prefix[j] : merge(prefix[j], promote(dp[e[0]], e));
			}
			for(int j = 0;j < g[cur].length;j++){
				int[] e = g[cur][g[cur].length-1-j];
				if(par[cur] != e[0]){
					fall[e[0]] = promote(merge(prefix[g[cur].length-1-j], suffix), e);
				}
				suffix = par[cur] == e[0] ? suffix : merge(suffix, promote(dp[e[0]], e));
			}
		}
		
		for(int i = 0;i < n;i++){
			dp[i] = merge(fall[i], dp[i]);
		}
		return dp;
	}
	
	public static long pow(long a, long n, long mod) {
		//		a %= mod;
		long ret = 1;
		int x = 63 - Long.numberOfLeadingZeros(n);
		for (; x >= 0; x--) {
			ret = ret * ret % mod;
			if (n << 63 - x < 0)
				ret = ret * a % mod;
		}
		return ret;
	}

	
	static int mod = 1000000007;
	static long i2 = invl(2, mod);
	

	
	public static long invl(long a, long mod) {
		long b = mod;
		long p = 1, q = 0;
		while (b > 0) {
			long c = a / b;
			long d;
			d = a;
			a = b;
			b = d % b;
			d = p;
			p = q;
			q = d - c * q;
		}
		return p < 0 ? p + mod : p;
	}


	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");
//		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 F().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)); }
}

yukicoder

結果

テストケース

ソースコード