結果

問題 No.3050 Prefix Removal
ユーザー 37zigen
提出日時 2025-01-21 00:12:41
言語 Java
(openjdk 23)
結果
AC  
実行時間 1,192 ms / 2,000 ms
コード長 3,611 bytes
コンパイル時間 2,901 ms
コンパイル使用メモリ 82,816 KB
実行使用メモリ 85,116 KB
最終ジャッジ日時 2025-03-07 20:32:39
合計ジャッジ時間 37,382 ms
ジャッジサーバーID
（参考情報） 		judge5 / 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
other AC * 55
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.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.NoSuchElementException;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws FileNotFoundException {
		new Main().run();
	}

	long mod = (long) 1e9 + 7;

	long[] fac = new long[100];
	long[] ifac = new long[100];
	long[] inv = new long[100];
	{
		Arrays.fill(fac, 1);
		Arrays.fill(ifac, 1);
		Arrays.fill(inv, 1);
		for (int i = 2; i < 100; ++i) {
			fac[i] = i * fac[i - 1] % mod;
			inv[i] = mod - mod / i * inv[(int) (mod % i)] % mod;
			ifac[i] = inv[i] * ifac[i - 1] % mod;
		}
	}
	
	long comb(int n, int k) {
		if (k < 0 || n - k < 0) return 0;
		return fac[n] * ifac[k] % mod * ifac[n - k] % mod;
	}
	
	void run() {
		//5e5*5e5*1e7=2.5e18
		PrintWriter pw = new PrintWriter(System.out);
		FastScanner sc = new FastScanner();
		int N = sc.nextInt();
		int K = sc.nextInt();
		long[] A = new long[N];
		for (int i = 0; i < N; ++i) {
			A[i] = sc.nextLong();
		}
		long[] sum = new long[N + 1];
		for (int i = N - 1; i >= 0; --i) {
			sum[i] = A[i] + sum[i + 1];
		}
		long[][] B = new long[N - 1][2];
		for (int i = 0; i < N - 1; ++i) {
			B[i][0] = sum[i + 1];
			B[i][1] = i + 1;
		}
		Arrays.sort(B, (x, y) -> -Long.compare(x[0], y[0]));
		int[] rank = new int[N];
		for (int i = 0 ; i < B.length; ++i) {
			rank[(int) B[i][1]] = i;
		}
		long s = 0;
		for (int i = 0; i < K - 1; ++i) {
			s += B[i][0];
		}
		int p = K - 1;
		long ans = Long.MIN_VALUE / 3;
		for (int i = N - 1; i >= K - 1; --i) {
			if (i != N - 1 && rank[i + 1] < p) {
				s -= sum[i + 1];
				++p;
				while (B[p - 1][1] > i) ++p;
				s += B[p - 1][0];
			}
			long v = s + sum[0] - K * sum[i + 1];
			ans = Math.max(ans, v);
		}
		pw.println(ans);
		pw.close();
	}
	static void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}
}


class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;
	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;}
	public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; 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 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 double nextDouble() { return Double.parseDouble(next());}
}
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