結果

問題 No.1144 Triangles
ユーザー uwiuwi
提出日時 2020-07-31 23:14:19
言語 Java21
(openjdk 21)
結果
AC  
実行時間 2,312 ms / 3,000 ms
コード長 5,029 bytes
コンパイル時間 4,475 ms
コンパイル使用メモリ 80,740 KB
実行使用メモリ 58,884 KB
最終ジャッジ日時 2023-09-21 02:31:54
合計ジャッジ時間 37,566 ms
ジャッジサーバーID
（参考情報） 		judge13 / judge15
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 42 ms
49,460 KB
testcase_01 AC 43 ms
49,476 KB
testcase_02 AC 42 ms
49,420 KB
testcase_03 AC 42 ms
49,816 KB
testcase_04 AC 2,278 ms
58,592 KB
testcase_05 AC 2,312 ms
58,412 KB
testcase_06 AC 2,140 ms
58,332 KB
testcase_07 AC 2,176 ms
58,400 KB
testcase_08 AC 2,255 ms
58,868 KB
testcase_09 AC 41 ms
49,448 KB
testcase_10 AC 42 ms
49,820 KB
testcase_11 AC 41 ms
49,508 KB
testcase_12 AC 42 ms
49,340 KB
testcase_13 AC 43 ms
49,504 KB
testcase_14 AC 2,172 ms
58,764 KB
testcase_15 AC 2,057 ms
57,004 KB
testcase_16 AC 2,194 ms
58,444 KB
testcase_17 AC 2,261 ms
58,740 KB
testcase_18 AC 2,209 ms
58,884 KB
testcase_19 AC 273 ms
56,776 KB
testcase_20 AC 73 ms
50,876 KB
testcase_21 AC 74 ms
51,256 KB
testcase_22 AC 2,100 ms
58,576 KB
testcase_23 AC 320 ms
56,932 KB
testcase_24 AC 2,174 ms
58,272 KB
testcase_25 AC 1,313 ms
58,528 KB
testcase_26 AC 210 ms
56,876 KB
testcase_27 AC 107 ms
55,984 KB
testcase_28 AC 925 ms
58,292 KB
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ソースコード

diff # 

package contest200731;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.InputMismatchException;

public class F {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		int[][] co = new int[n][];
		for(int i = 0;i < n;i++) {
			co[i] = na(2);
		}
		
		// ad-bc
		long ans = 0;
		for(int i = 0;i < n;i++) {
			int[][] lco = new int[n-1][];
			int p = 0;
			for(int j = 0;j < n;j++) {
				if(!(co[i][0] == co[j][0] && co[i][1] == co[j][1])) {
					lco[p++] = new int[] {co[j][0] - co[i][0], co[j][1] - co[i][1]};
				}
			}
			ans += go(Arrays.copyOf(lco, p));
		}
		ans %= mod;
		ans = ans * invl(3, mod) % mod;
		out.println(ans);
	}
	
	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;
	}

	
	int mod = 1000000007;
	
	long go(int[][] co)
	{
		int n = co.length;
		Arrays.sort(co, compArgi);
		int j = 0;
		long xsum = 0;
		long ysum = 0;
		long ret = 0;
		for(int i = 0;i < n;i++) {
			while(j < i+n && cross(co[i], co[j%n]) >= 0) {
				if(cross(co[i], co[j%n]) == 0 && dot(co[i], co[j%n]) > 0 && j%n < i)break;
				xsum += co[j%n][0];
				ysum += co[j%n][1];
				j++;
			}
			xsum -= co[i][0];
			ysum -= co[i][1];
			ret += co[i][0] * ysum - co[i][1] * xsum;
			ret %= mod;
		}
		if(ret < 0)ret += mod;
		return ret;
	}
	
	public static long dot(int[] a, int[] b){ return (long)a[0]*b[0]+(long)a[1]*b[1]; }
	public static long cross(int[] a, int[] b){ return (long)a[0]*b[1]-(long)a[1]*b[0];	}
	
	public static int ccw(int[] a, int[] b, int[] t){ return Long.signum((long)(t[0]-a[0])*(b[1]-a[1])-(long)(b[0]-a[0])*(t[1]-a[1])); }

	
	public static Comparator<int[]> compArgi = new Comparator<int[]>(){
		public int compare(int[] a, int[] b)
		{
			long ax = a[0], ay = a[1];
			long bx = b[0], by = b[1];
			int za = ay > 0 || ay == 0 && ax > 0 ? 0 : 1;
			int zb = by > 0 || by == 0 && bx > 0 ? 0 : 1;
			if(za != zb)return za - zb;
			if(ay*bx-ax*by != 0)return Long.signum(ay*bx-ax*by);
			return Long.signum((ax*ax+ay*ay)-(bx*bx+by*by));
		}
	};

	
	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)); }
}
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