Submission #301704

#	Time	Username	Problem	Language	Result	Execution time	Memory
301704		ijxjdjd	Carnival Tickets (IOI20_tickets)	Java	76 / 100	3078 ms	226556 KiB

tickets

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;

public class tickets {
	long find_maximum(int K, int[][] x) {
		int N = x.length;
		int M = x[0].length;
		int[][] S = new int[N*K][2];
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < K; j++) {
				S[i*K + j][0] = i;
				S[i*K + j][1] = j;
			}
		}
		Arrays.sort(S, new Comparator<int[]>() {
			@Override
			public int compare(int[] ints, int[] t1) {
				return -Integer.compare(-x[ints[0]][ints[1]] - x[ints[0]][M - K + ints[1]], -x[t1[0]][t1[1]] - x[t1[0]][M-K+t1[1]]);
			}
		});
		long res = 0;
		ArrayList<Integer>[] low = new ArrayList[N];
		int[] count = new int[N];
		for (int i = 0; i < S.length/2; i++) {
			count[S[i][0]]++;
		}
		int[][] ans = new int[N][M];
		ArrayList<int[]>[] rounds = new ArrayList[K];
		for (int j = 0; j < K; j++) {
			rounds[j] = new ArrayList<>();
		}
		int k = 0;
		for (int id = 0; id < N; id++) {
			int bef = k;
			if (count[id] == 0) {
				for (int c = 1; c <= K; c++) {
					rounds[k].add(new int[]{id, M - c});
					res += x[id][M - c];
					k++;
					if (k == K) {
						k = 0;
					}
				}
			}
			else {
				for (int a = 0 ; a < count[id]; a++) {
					rounds[k].add(new int[]{id, a});
					res -= x[id][a];
					k++;
					if (k == K) {
						k = 0;
					}
				}
				int c = 1;
				for (int i = k; i != bef; ) {
					res += x[id][M - c];
					rounds[i].add(new int[]{id, M - c});
					c++;
					i++;
					if (i == K) {
						i = 0;
					}
				}
			}
		}
		for (int j = 0; j < N; j++) {
			Arrays.fill(ans[j], -1);
		}
		for (int j = 0; j < K; j++) {
			for (int[] s : rounds[j]) {
				ans[s[0]][s[1]] = j;
			}
		}
		grader.allocate_tickets(ans);
		return res;
	}

}

Compilation message (stderr)

Note: tickets.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 14 / 14
• Subtask 4: 0 / 14
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23
• Subtask 7: 0 / 10