結果

問題 No.696 square1001 and Permutation 5
コンテスト
ユーザー しらっ亭
提出日時 2018-06-09 00:19:55
言語 Java
(openjdk 23)
結果
TLE  
実行時間 -
コード長 4,400 bytes
コンパイル時間 4,015 ms
コンパイル使用メモリ 79,708 KB
実行使用メモリ 74,856 KB
最終ジャッジ日時 2024-06-30 11:47:39
合計ジャッジ時間 42,949 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge5
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 * 10 TLE * 2
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.math.BigInteger;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.Scanner;

public class Sol {
    InputStream is;
    PrintWriter out;
    String INPUT = "";

    void solve() {
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        int n = ni();
        int[] A = na(n);

        /*
        {
            n = 100000;
            A = new int[n];
            for (int i = 0; i < n; i++) {
                A[i] = n-i;
            }
        }
        */

        BinaryIndexedTree ft = new BinaryIndexedTree(n);

        long[] factSum = new long[n];

        for (int i = 0; i < n - 1; i++) {
            int a = A[i];
            int cnt = a-1-ft.sum(a);
            int len = n - i;
            factSum[len-1] += cnt;
            ft.add(a, 1);
        }
//        System.out.println(Arrays.toString(factSum));

        BigInteger ans = BigInteger.ONE;
        BigInteger fact = BigInteger.ONE;

        for (int i = 1; i < n; i++) {
            fact = fact.multiply(BigInteger.valueOf(i));
            if (factSum[i] > 0) {
                ans = ans.add(fact.multiply(BigInteger.valueOf(factSum[i])));
            }
        }

        System.out.println(ans);
    }

    public static void main(String[] args) throws Exception {
        new Sol().solve();
    }

    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)); }

}

class BinaryIndexedTree {
    private int n;
    private int[] val;

    public BinaryIndexedTree(int n) {
        this.n = n;
        val = new int[n];
    }

    public void add(int i, int x) {
        for (; i < n; i |= i + 1) val[i] += x;
    }

    int sum(int i) {
        int s = 0;
        --i;
        if (i >= n) i = n - 1;
        for (; i >= 0; i = (i & (i + 1)) - 1) s += val[i];
        return s;
    }
}
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