結果

問題 No.1193 Penguin Sequence
ユーザー uwiuwi
提出日時 2020-08-22 16:12:00
言語 Java21
(openjdk 21)
結果
AC  
実行時間 399 ms / 2,000 ms
コード長 5,594 bytes
コンパイル時間 6,760 ms
コンパイル使用メモリ 87,708 KB
実行使用メモリ 60,040 KB
最終ジャッジ日時 2023-08-05 13:14:17
合計ジャッジ時間 17,512 ms
ジャッジサーバーID
（参考情報） 		judge14 / judge11
このコードへのチャレンジ（β）

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 200 ms
55,080 KB
testcase_01 AC 335 ms
57,896 KB
testcase_02 AC 309 ms
56,732 KB
testcase_03 AC 317 ms
56,348 KB
testcase_04 AC 329 ms
60,040 KB
testcase_05 AC 399 ms
57,712 KB
testcase_06 AC 387 ms
57,184 KB
testcase_07 AC 314 ms
57,484 KB
testcase_08 AC 311 ms
57,400 KB
testcase_09 AC 308 ms
57,064 KB
testcase_10 AC 300 ms
57,712 KB
testcase_11 AC 273 ms
56,832 KB
testcase_12 AC 275 ms
56,496 KB
testcase_13 AC 291 ms
57,748 KB
testcase_14 AC 265 ms
55,952 KB
testcase_15 AC 289 ms
57,584 KB
testcase_16 AC 202 ms
56,220 KB
testcase_17 AC 43 ms
49,524 KB
testcase_18 AC 101 ms
51,020 KB
testcase_19 AC 303 ms
57,788 KB
testcase_20 AC 274 ms
56,556 KB
testcase_21 AC 239 ms
56,112 KB
testcase_22 AC 107 ms
53,000 KB
testcase_23 AC 256 ms
56,204 KB
testcase_24 AC 234 ms
56,948 KB
testcase_25 AC 140 ms
53,928 KB
testcase_26 AC 75 ms
52,244 KB
testcase_27 AC 265 ms
56,436 KB
testcase_28 AC 279 ms
55,412 KB
testcase_29 AC 282 ms
56,612 KB
testcase_30 AC 164 ms
56,256 KB
testcase_31 AC 168 ms
53,684 KB
testcase_32 AC 230 ms
57,304 KB
testcase_33 AC 238 ms
57,236 KB
testcase_34 AC 207 ms
56,156 KB
testcase_35 AC 236 ms
56,984 KB
testcase_36 AC 210 ms
56,172 KB
testcase_37 AC 288 ms
56,152 KB
testcase_38 AC 44 ms
49,428 KB
testcase_39 AC 45 ms
49,480 KB
testcase_40 AC 46 ms
49,476 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 gioku2020day1;
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 L {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int n = ni();
		int[] a = na(n);
		a = shrink(a);
		long inv = 0;
		{
			int[] ft = new int[n+5];
			for(int i = n-1;i >= 0;i--){
				inv += sumFenwick(ft, a[i]-1);
				addFenwick(ft, a[i], 1);
			}
		}
		long rinv = 0;
		{
			int[] ft = new int[n+5];
			for(int i = 0;i < n;i++){
				rinv += sumFenwick(ft, a[i]-1);
				addFenwick(ft, a[i], 1);
			}
		}
		
		int mod = 998244353;
		inv %= mod;
		rinv %= mod;
		
		long u = n;
		long s2 = u*(u-1)%mod*(u+1)%mod*(3*u+2)%mod*invl(24,mod)%mod;
		s2 = s2 % mod * invl(u*u%mod, mod) % mod;
		long S2 = s2;
		long mul = invl(u*(u-1)%mod, mod);
		long l = 0;
		for(int i = 1;i <= n;i++){
			l += (long)i*(i-1);
		}
		S2 += l%mod*mul;
		S2 %= mod;
		
		int[][] fif = enumFIF(n, mod);
		long ans = s2*rinv + S2*inv;
		ans %= mod;
		for(int i = 1;i <= n;i++){
			ans = ans * C(n, i, mod, fif) % mod;
		}
		out.println(ans);
	}
	
	public static long C(int n, int r, int mod, int[][] fif) {
		if (n < 0 || r < 0 || r > n)
			return 0;
		return (long) fif[0][n] * fif[1][r] % mod * fif[1][n - r] % mod;
	}

	
	public static int[][] enumFIF(int n, int mod) {
		int[] f = new int[n + 1];
		int[] invf = new int[n + 1];
		f[0] = 1;
		for (int i = 1; i <= n; i++) {
			f[i] = (int) ((long) f[i - 1] * i % mod);
		}
		long a = f[n];
		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;
		}
		invf[n] = (int) (p < 0 ? p + mod : p);
		for (int i = n - 1; i >= 0; i--) {
			invf[i] = (int) ((long) invf[i + 1] * (i + 1) % mod);
		}
		return new int[][] { f, invf };
	}

	
	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 sumFenwick(int[] ft, int i)
	{
		int sum = 0;
		for(i++;i > 0;i -= i&-i)sum += ft[i];
		return sum;
	}
	
	public static void addFenwick(int[] ft, int l, int r, int v)
	{
		addFenwick(ft, l, v);
		addFenwick(ft, r, -v);
	}
	
	public static void addFenwick(int[] ft, int i, int v)
	{
		if(v == 0 || i < 0)return;
		int n = ft.length;
		for(i++;i < n;i += i&-i)ft[i] += v;
	}

	
	public static int[] shrink(int[] a) {
		int n = a.length;
		long[] b = new long[n];
		for (int i = 0; i < n; i++)
			b[i] = (long) a[i] << 32 | i;
		Arrays.sort(b);
		int[] ret = new int[n];
		int p = 0;
		for (int i = 0; i < n; i++) {
			if (i > 0 && (b[i] ^ b[i - 1]) >> 32 != 0)
				p++;
			ret[(int) b[i]] = p;
		}
		return ret;
	}

	
	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 L().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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