結果

問題 No.1023 Cyclic Tour
ユーザー uwiuwi
提出日時 2020-04-10 23:00:06
言語 Java21
(openjdk 21)
結果
AC  
実行時間 304 ms / 2,000 ms
コード長 6,308 bytes
コンパイル時間 4,179 ms
コンパイル使用メモリ 87,492 KB
実行使用メモリ 54,440 KB
最終ジャッジ日時 2024-09-15 23:34:29
合計ジャッジ時間 18,175 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge6
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 50 ms
36,788 KB
testcase_01 AC 52 ms
37,004 KB
testcase_02 AC 51 ms
36,952 KB
testcase_03 AC 51 ms
36,768 KB
testcase_04 AC 107 ms
40,944 KB
testcase_05 AC 105 ms
41,200 KB
testcase_06 AC 110 ms
41,712 KB
testcase_07 AC 107 ms
41,448 KB
testcase_08 AC 117 ms
41,172 KB
testcase_09 AC 203 ms
46,456 KB
testcase_10 AC 213 ms
46,052 KB
testcase_11 AC 218 ms
49,056 KB
testcase_12 AC 217 ms
50,068 KB
testcase_13 AC 223 ms
50,184 KB
testcase_14 AC 225 ms
50,552 KB
testcase_15 AC 228 ms
50,452 KB
testcase_16 AC 264 ms
50,336 KB
testcase_17 AC 240 ms
54,440 KB
testcase_18 AC 304 ms
50,276 KB
testcase_19 AC 303 ms
50,460 KB
testcase_20 AC 256 ms
50,348 KB
testcase_21 AC 255 ms
50,228 KB
testcase_22 AC 261 ms
50,192 KB
testcase_23 AC 282 ms
50,320 KB
testcase_24 AC 297 ms
50,228 KB
testcase_25 AC 255 ms
50,172 KB
testcase_26 AC 256 ms
50,284 KB
testcase_27 AC 236 ms
50,388 KB
testcase_28 AC 287 ms
50,288 KB
testcase_29 AC 296 ms
50,112 KB
testcase_30 AC 285 ms
50,108 KB
testcase_31 AC 258 ms
50,144 KB
testcase_32 AC 289 ms
50,144 KB
testcase_33 AC 274 ms
50,396 KB
testcase_34 AC 105 ms
44,452 KB
testcase_35 AC 139 ms
45,996 KB
testcase_36 AC 262 ms
50,264 KB
testcase_37 AC 284 ms
50,120 KB
testcase_38 AC 294 ms
50,196 KB
testcase_39 AC 279 ms
50,260 KB
testcase_40 AC 275 ms
50,244 KB
testcase_41 AC 261 ms
50,464 KB
testcase_42 AC 152 ms
46,720 KB
testcase_43 AC 137 ms
45,576 KB
testcase_44 AC 171 ms
45,248 KB
testcase_45 AC 256 ms
50,656 KB
testcase_46 AC 255 ms
50,892 KB
testcase_47 AC 161 ms
48,972 KB
testcase_48 AC 251 ms
50,268 KB
testcase_49 AC 258 ms
50,076 KB
testcase_50 AC 242 ms
50,120 KB
testcase_51 AC 145 ms
46,856 KB
testcase_52 AC 149 ms
46,308 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 # 

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 D2 {
	InputStream is;
	PrintWriter out;
//	String INPUT = "3 4 1 2 2 2 3 2 3 2 2 2 1 2";
	String INPUT = "";
	
	// 1-3
	//  /^
	// 2>4
	
	// 1-2
	// ^/^
	// 3-4
	
	void solve()
	{
		int n =ni(), m = ni();
		int[] from = new int[2*m];
		int[] to = new int[2*m];
		int[] ws = new int[2*m];
		int p = 0;
		DJSet ds = new DJSet(n);
		for(int i = 0;i < m;i++){
			int x = ni()-1, y = ni()-1, c = ni();
			from[p] = x; to[p] = y; ws[p] = c;p++;
			if(c == 1 && ds.union(x, y)){
				out.println("Yes");
				return;
			}
		}
		
		int q = 0;
		for(int i = 0;i < m;i++){
			if(ws[i] == 2){
				from[q] = ds.root(from[i]);
				to[q] = ds.root(to[i]);
				if(from[q] == to[q]){
					out.println("Yes");
					return;
				}
				q++;
			}
		}
		
		int[][] g = packD(n, from, to, q);
		int[] clus = decomposeToSCCNoRec(g);
		int max = 0;
		for(int u : clus)max = Math.max(max, u);
		if(max+1 < n){
			out.println("Yes");
		}else{
			out.println("No");
		}
	}
	public static int[] decomposeToSCCNoRec(int[][] g)
	{
		int n = g.length;
		int[] stack = new int[n+1];
		int[] ind = new int[n+1];
		int[] ord = new int[n];
		Arrays.fill(ord, -1);
		int[] low = new int[n];
		Arrays.fill(low, -1);
		int sp = 0;
		int id = 0; // preorder
		int[] clus = new int[n];
		int cid = 0;
		int[] cstack = new int[n+1];
		int csp = 0;
		boolean[] incstack = new boolean[n];
		for(int i = 0;i < n;i++){
			if(ord[i] == -1){
				ind[sp] = 0;
				cstack[csp++] = i;
				stack[sp++] = i;
				incstack[i] = true;
				while(sp > 0){
					int cur = stack[sp-1];
					if(ind[sp-1] == 0){
						ord[cur] = low[cur] = id++;
					}
					if(ind[sp-1] < g[cur].length){
						int nex = g[cur][ind[sp-1]];
						if(ord[nex] == -1){
							ind[sp-1]++;
							ind[sp] = 0;
							incstack[nex] = true;
							cstack[csp++] = nex;
							stack[sp++] = nex;
						}else{
							// shortcut
//							U.tr(cur, nex, incstack[nex], low[nex], stack);
							if(incstack[nex])low[cur] = Math.min(low[cur], ord[nex]); // low is ok too, but slower.
							ind[sp-1]++;
						}
					}else{
						if(ord[cur] == low[cur]){
							while(csp > 0){
								incstack[cstack[csp-1]] = false;
								clus[cstack[--csp]] = cid;
								if(cstack[csp] == cur)break;
							}
							cid++;
						}
						if(--sp >= 1)low[stack[sp-1]] = Math.min(low[stack[sp-1]], low[stack[sp]]);
					}
				}
			}
		}
		return clus;
	}

	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[][] packD(int n, int[] from, int[] to){ return packD(n, from, to, from.length);}
	public static int[][] packD(int n, int[] from, int[] to, int sup)
	{
		int[][] g = new int[n][];
		int[] p = new int[n];
		for(int i = 0;i < sup;i++)p[from[i]]++;
		for(int i = 0;i < n;i++)g[i] = new int[p[i]];
		for(int i = 0;i < sup;i++){
			g[from[i]][--p[from[i]]] = to[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 D2().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)); }
}
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