結果

問題 No.551 夏休みの思い出（２）
コンテスト
ユーザー uwi
提出日時 2017-07-28 22:36:25
言語 Java
(openjdk 23)
結果
AC  
実行時間 224 ms / 4,000 ms
コード長 4,757 bytes
コンパイル時間 4,442 ms
コンパイル使用メモリ 87,160 KB
実行使用メモリ 49,748 KB
最終ジャッジ日時 2024-10-10 05:13:59
合計ジャッジ時間 12,646 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 47
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 contest170728;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Random;

public class E {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int P = ni(), R = ni(); // :)
		Random gen = new Random();
		for(int Q = ni();Q > 0;Q--){
			long a = ni(), b = ni(), c = ni();
			long s = (b*b-4L*a*c)%P;
			if(s < 0)s += P;
			long ia = invl(2*a, P);
			if(pow(s, (P-1)/2, P) == P-1){
				out.println(-1);
				continue;
			}
			if(s == 0){
				out.println(((-b)*ia%P+P)%P);
				continue;
			}
			long t = sqrt(s, P, gen);
			long[] anss = {((-b+t)*ia%P+P)%P, ((-b-t)*ia%P+P)%P};
			Arrays.sort(anss);
			for(long v : anss){
				out.print(v + " ");
			}
			out.println();
		}
	}
	
	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 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;
	}

	
	public static long sqrt(long n, int p, Random gen)
	{
		if(n == 0)return 0;
		int S = Integer.numberOfTrailingZeros(p-1);
		long Q = p-1>>>S;
		if(S == 1){
			return pow(n, (p+1)/4, p);
		}
		
		int z = 0;
		do{
			z = gen.nextInt(p-1)+1;
		}while(pow(z, (p-1)/2, p) != p-1);
		
		long c = pow(z, Q, p);
		long R = pow(n, (Q+1)/2, p);
		long t = pow(n, Q, p);
		int M = S;
		while(t != 1){
			long u = t;
			for(int i = 1;i < M;i++){
				u = u * u % p;
//				U.tr(i, t, u);
				if(u == 1){
					long b = c;
					for(int j = 0;j < M-i-1;j++){
						b = b * b % p;
					}
					R = R * b % p;
					t = t * b % p * b % p;
					c = b * b % p;
					M = i;
					break;
				}
			}
		}
		return R;
	}

	
	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 E().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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