제출 #240508

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
240508		conankun	수열 (APIO14_sequence)	Java	60 / 100	499 ms	31668 KiB

sequence

import java.io.*;
import java.util.*;
public class sequence {
    static int N,K;
    static long S[];
    static long D[][];
    static short OPT1[][];
    static byte OPT2[][];
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        st = new StringTokenizer(br.readLine());
        N = Integer.parseInt(st.nextToken());
        K = Integer.parseInt(st.nextToken());
      	S = new long[N + 1];
      	D = new long[2][N + 1];
      	OPT1 = new short[K + 1][N + 1];
      	OPT2 = new byte[K + 1][N + 1];
        st = new StringTokenizer(br.readLine());
        for(int i = 1 ; i <= N ; i++) {
            S[i] = Integer.parseInt(st.nextToken());
            S[i] += S[i-1];
        }
        br.close();
        solve();
    }
    private static boolean canSkip(int k, int i, int j,int threshold) {
        return (D[(k-1)%2][i] - D[(k-1)%2][j] + S[N] * (S[j] - S[i]))
                <= threshold * (S[j] - S[i]);
    }
    private static boolean canRemoveLastCandidate(int k, int i, int j, int l) {
        return (D[(k-1)%2][i] - D[(k-1)%2][j] + S[N] * (S[j] - S[i])) * (S[l] - S[j])
                <= (D[(k-1)%2][j] - D[(k-1)%2][l] + S[N] * (S[l] - S[j])) * (S[j] - S[i]);
    }
    private static void dp(int k) {
        int [] candid = new int[N];
      	int front = 0, back = 0;
      	candid[back++] = k -1;
        for(int i = k ; i <= N ; i++) {
            while (back - front > 1 && canSkip(k, candid[front], candid[front + 1], (int) S[i])) {
                front++;
            }
                int j = candid[front];
          		OPT2[k][i] = (byte)(j / 60000);
          		OPT1[k][i] = (short)(j - OPT2[k][i] * 60000);
                D[(k%2)][i] = D[(k-1)%2][j] + S[i] * S[j] - S[N] * S[j] + S[N] * S[i] - (S[i] * S[i]);
            while (back - front > 1
                    && canRemoveLastCandidate(k, i, candid[back-1], candid[back-2])) {
                back--;
            }
            candid[back++]=i;
        }
    }
    private static void solve() throws IOException {
        for(int k = 1 ; k <= K ; k++) {
            Arrays.fill(D[k%2], 0);
            dp(k);
        }
        long ret = 0; int ind = 1;
        for(int i = 1 ; i <= N ; i++) {
            if(ret < D[K%2][i]) {
                ret = D[K%2][i];
                ind = i;
            }
        }
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        bw.write(ret+"\n");
        int[] opt = new int[K];
        int front = 0;
        int k = K;
        while (k > 0) {
            opt[front++]=ind;
            ind = (int)OPT2[k][ind] * 60000 + (int)OPT1[k--][ind];
            
        }
        for(int i = K - 1; i >= 0; i--) {
            bw.write(opt[i]+" ");
        }
      	bw.flush();
        bw.close();
    }
}

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