結果

問題 No.121 傾向と対策：門松列（その２）
ユーザー ぴろずぴろず
提出日時 2015-03-12 21:28:12
言語 Java21
(openjdk 21)
結果
AC  
実行時間 3,797 ms / 5,000 ms
コード長 5,946 bytes
コンパイル時間 3,228 ms
コンパイル使用メモリ 83,184 KB
実行使用メモリ 135,708 KB
最終ジャッジ日時 2023-09-11 04:02:58
合計ジャッジ時間 19,538 ms
ジャッジサーバーID
（参考情報） 		judge14 / judge13
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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 306 ms
56,580 KB
testcase_01 AC 431 ms
61,596 KB
testcase_02 AC 130 ms
54,776 KB
testcase_03 AC 959 ms
130,060 KB
testcase_04 AC 3,797 ms
135,508 KB
testcase_05 AC 1,027 ms
132,992 KB
testcase_06 AC 1,823 ms
132,176 KB
testcase_07 AC 2,863 ms
135,708 KB
testcase_08 AC 3,090 ms
135,588 KB
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ソースコード

diff # 

package no121;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.NoSuchElementException;

public class Main {

	public static void main(String[] args) {
		IO io = new IO();
		int n = io.nextInt();
		int[] a = io.arrayInt(n);
		long ans = 0;
		ans += count(n,a);
		for(int i=0;i<n;i++) {
			a[i] = 1000000001 - a[i];
		}
		ans += count(n,a);
		ans -= count2(n,a);
		System.out.println(ans);
	}

	static long count(int n,int[] a) {
		Pair[] p = new Pair[n];
		for(int i=0;i<n;i++) {
			p[i] = new Pair(a[i], i);
		}
		Arrays.sort(p, (x,y) -> Integer.compare(x.v, y.v));
		BIT bit = new BIT(n);
		int used = 0;
		long sum = 0;
		for(int i=0;i<n;i++) {
			if (p[i].v > used) {
				used = p[i].v;
				for(int j=i;j<n;j++) {
					if (p[j].v > used) {
						break;
					}
					bit.accumlate(p[j].i, 1);
				}
			}
			int j = p[i].i;
			long left = j - bit.sum(0, j);
			long right = n - 1 - j - bit.sum(j + 1, n);
			sum += left * right;
		}
		return sum;
	}

	static long count2(int n,int[] a) {
		long sum = 0;
		Pair[] p = new Pair[n];
		for(int i=0;i<n;i++) {
			p[i] = new Pair(a[i], i);
		}
		Arrays.sort(p, (x,y) -> Integer.compare(x.v, y.v));
		for(int i=0;i<n;) {
			ArrayList<Integer> index = new ArrayList<>();
			int f = i;
			for(;i<n && p[f].v == p[i].v;i++) {
				index.add(p[i].i);
			}
			for(int j=0;j<index.size()-1;j++) {
				long g = index.get(j+1) - index.get(j) - 1;
				sum += g * (j+1) * (index.size() - 1 - j);

			}
		}
		return sum;
	}

	static class Pair {
		int v,i;
		public Pair(int v,int i) {
			this.v = v;
			this.i = i;
		}
	}
}
/* 0-indexed */
class BIT {
	private int n;
	private long[] bit;
	public BIT(int n) {
		this.n = n;
		bit = new long[n+1];
	}

	public void accumlate(int index,long num) {
		index++;
		while(index<=n) {
			bit[index] += num;
			index+=index&-index;
		}
	}

	/* [begin , end) */
	public long sum(int begin,int end) {
		return sum(end) - sum(begin);
	}

	private long sum(int i) {
		long s = 0;
		while(i>0) {
			s+=bit[i];
			i-=i&-i;
		}
		return s;
	}

	public long get(int index) {
		return sum(index,index+1);
	}

	public void set(int index,long num) {
		accumlate(index,num-(sum(index)-sum(index-1)));
	}

	public String toString() {
		long[] value = new long[n];
		for(int i=0;i<n;i++) {
			value[i] = get(i);
		}
		return Arrays.toString(value);
	}
}
class IO {
	private final InputStream in;
	final PrintWriter out = new PrintWriter(System.out);
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;

	public IO() { this(System.in);}
	public IO(InputStream source) { this.in = source;}
	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		}else{
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}
	private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
	private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
	private static boolean isNewLine(int c) { return c == '\n' || c == '\r';}
	private void skipUnprintable() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;}
	private void skipNewLine() { while(hasNextByte() && isNewLine(buffer[ptr])) ptr++;}
	public boolean hasNext() { skipUnprintable(); return hasNextByte();}
	public boolean hasNextLine() { skipNewLine(); return hasNextByte();}
	public String next() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while(isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	public char[] nextCharArray(int len) {
		char[] s = new char[len];
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		int i = 0;
		int b = readByte();
		while(isPrintableChar(b)) {
			if (i == len) {
				throw new InputMismatchException();
			}
			s[i++] = (char) b;
			b = readByte();
		}
		return s;
	}
	public String nextLine() {
		if (!hasNextLine()) {
			throw new NoSuchElementException();
		}
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while(!isNewLine(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	public long nextLong() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while(true){
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			}else if(b == -1 || !isPrintableChar(b)){
				return minus ? -n : n;
			}else{
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}
	public int nextInt() {
		long nl = nextLong();
		if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) {
			throw new NumberFormatException();
		}
		return (int) nl;
	}
	public char nextChar() {
		if (!hasNext()) {
			throw new NoSuchElementException();
		}
		return (char) readByte();
	}
	public double nextDouble() { return Double.parseDouble(next());}
	public int[] arrayInt(int n) { int[] a = new int[n]; for(int i=0;i<n;i++) a[i] = nextInt(); return a;}
	public long[] arrayLong(int n) { long[] a = new long[n]; for(int i=0;i<n;i++) a[i] = nextLong(); return a;}
	public double[] arrayDouble(int n) { double[] a = new double[n]; for(int i=0;i<n;i++) a[i] = nextDouble(); return a;}
	public void arrayInt(int[]... a) {for(int i=0;i<a[0].length;i++) for(int j=0;j<a.length;j++) a[j][i] = nextInt();}
	public int[][] matrixInt(int n,int m) { int[][] a = new int[n][]; for(int i=0;i<n;i++) a[i] = arrayInt(m); return a;}
	public char[][] charMap(int n,int m) { char[][] a = new char[n][]; for(int i=0;i<n;i++) a[i] = nextCharArray(m); return a;}
}
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