Submission #336427

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
336427	2020-12-15T10:16:23 Z	ncduy0303	Feast (NOI19_feast)	C++17	100 / 100	127 ms	13540 KB

feast

/* NOI 2019: Feast
Idea: Greedy (combine adjacent values with the same sign and remove negative values from the two ends)
Time Complexity: O(NlogN)
*/

#include <bits/stdc++.h>

using namespace std;

const int INF = 1 << 30;
const int MAX_N = 300000 + 5;
const int MAX_L = 20; // ~ Log N
const long long MOD = 1e9 + 7;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef vector<vi> vvi;

#define LSOne(S) (S & (-S))
#define isBitSet(S, i) ((S >> i) & 1)

struct block{
    int id, l, r;
	long long sum;
};

int N, K;
block b[MAX_N];
long long arr[MAX_N];
bool v[MAX_N];
priority_queue<pair<long long, int> > pq;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);

    cin >> N >> K;
    for(int i = 0; i < N; i++) cin >> arr[i];

    int j, idx = 0;
    for(int i = 0; i < N; i = j) {
		b[idx].sum = 0;
		b[idx].l = idx - 1;
		b[idx].r = idx + 1;

		for(j = i; j < N && (arr[i] * arr[j] >= 0); j++) // arr[i] and arr[j] must have the same sign
			b[idx].sum += arr[j];

		if(!(b[idx].sum < 0 && idx == 0)) idx++; // remove the first block if it is negative
	}

	if(idx != 0 && b[idx - 1].sum < 0) idx--; // remove the last block if it is negative
	if(idx == 0) { // if after remove, there's nothing left
		cout << 0;
		return 0;
	}

    b[0].l = b[idx - 1].r = -1; // extreme end points
	int remaining = idx / 2 + 1;
	for (int i = 0; i < idx; i++)
		pq.push({-abs(b[i].sum), i}); // negative of absolute value to have a min priority queue

    memset(v, 0, sizeof(v));
	while(remaining > K) {
		int i = pq.top().second; pq.pop();
		if(v[i]) continue;
		v[i] = true;
		remaining--;

		//merge it with left and right
		if (b[i].l == -1) { //extreme left
			v[b[i].r] = true;
			b[b[b[i].r].r].l = -1;
		}
		else if (b[i].r == -1) { //extreme right
			v[b[i].l] = true;
			b[b[b[i].l].l].r = -1;
		}
		else {
			v[b[i].r] = true;
			v[b[i].l] = true;

			b[i].sum += b[b[i].l].sum + b[b[i].r].sum;
			if (b[b[i].l].l != -1) {
				b[b[b[i].l].l].r = i;
			}
			b[i].l = b[b[i].l].l;
			if (b[b[i].r].r != -1) {
				b[b[b[i].r].r].l = i;
			}
			b[i].r = b[b[i].r].r;

			v[i] = 0;
			pq.push({-abs(b[i].sum), i});
		}
	}

	long long ans = 0;
	for(int i = 0; i < idx; i++)
		if (!v[i] && b[i].sum > 0)
			ans += b[i].sum;

	cout << ans;
}

Subtask #1
4.0 / 4.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	44 ms	5740 KB	Output is correct
2	Correct	36 ms	5868 KB	Output is correct
3	Correct	47 ms	5868 KB	Output is correct
4	Correct	36 ms	5868 KB	Output is correct
5	Correct	36 ms	5868 KB	Output is correct
6	Correct	35 ms	5760 KB	Output is correct
7	Correct	35 ms	5740 KB	Output is correct
8	Correct	39 ms	5996 KB	Output is correct
9	Correct	35 ms	5740 KB	Output is correct
10	Correct	35 ms	5740 KB	Output is correct

Subtask #2
8.0 / 8.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	24 ms	4204 KB	Output is correct
2	Correct	24 ms	4076 KB	Output is correct
3	Correct	26 ms	4076 KB	Output is correct
4	Correct	29 ms	4076 KB	Output is correct
5	Correct	43 ms	5740 KB	Output is correct
6	Correct	24 ms	4076 KB	Output is correct
7	Correct	24 ms	4076 KB	Output is correct
8	Correct	45 ms	5868 KB	Output is correct
9	Correct	36 ms	5868 KB	Output is correct
10	Correct	30 ms	4204 KB	Output is correct

Subtask #3
18.0 / 18.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	107 ms	13444 KB	Output is correct
2	Correct	102 ms	13284 KB	Output is correct
3	Correct	105 ms	13412 KB	Output is correct
4	Correct	104 ms	13284 KB	Output is correct
5	Correct	109 ms	13412 KB	Output is correct
6	Correct	106 ms	13412 KB	Output is correct
7	Correct	97 ms	13412 KB	Output is correct
8	Correct	96 ms	13412 KB	Output is correct
9	Correct	102 ms	13540 KB	Output is correct
10	Correct	127 ms	13540 KB	Output is correct

Subtask #4
10.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	620 KB	Output is correct
2	Correct	1 ms	620 KB	Output is correct
3	Correct	1 ms	620 KB	Output is correct
4	Correct	1 ms	620 KB	Output is correct
5	Correct	1 ms	620 KB	Output is correct
6	Correct	1 ms	620 KB	Output is correct
7	Correct	1 ms	620 KB	Output is correct
8	Correct	1 ms	620 KB	Output is correct
9	Correct	1 ms	620 KB	Output is correct
10	Correct	1 ms	620 KB	Output is correct

Subtask #5
11.0 / 11.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	620 KB	Output is correct
2	Correct	1 ms	620 KB	Output is correct
3	Correct	1 ms	620 KB	Output is correct
4	Correct	1 ms	620 KB	Output is correct
5	Correct	1 ms	620 KB	Output is correct
6	Correct	1 ms	620 KB	Output is correct
7	Correct	1 ms	620 KB	Output is correct
8	Correct	1 ms	620 KB	Output is correct
9	Correct	1 ms	620 KB	Output is correct
10	Correct	1 ms	620 KB	Output is correct
11	Correct	1 ms	620 KB	Output is correct
12	Correct	1 ms	620 KB	Output is correct
13	Correct	1 ms	620 KB	Output is correct
14	Correct	1 ms	620 KB	Output is correct
15	Correct	1 ms	620 KB	Output is correct
16	Correct	1 ms	620 KB	Output is correct
17	Correct	1 ms	620 KB	Output is correct
18	Correct	1 ms	748 KB	Output is correct
19	Correct	1 ms	620 KB	Output is correct
20	Correct	1 ms	620 KB	Output is correct

Subtask #6
20.0 / 20.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	620 KB	Output is correct
2	Correct	1 ms	620 KB	Output is correct
3	Correct	1 ms	620 KB	Output is correct
4	Correct	1 ms	620 KB	Output is correct
5	Correct	1 ms	620 KB	Output is correct
6	Correct	1 ms	620 KB	Output is correct
7	Correct	1 ms	620 KB	Output is correct
8	Correct	1 ms	620 KB	Output is correct
9	Correct	1 ms	620 KB	Output is correct
10	Correct	1 ms	620 KB	Output is correct
11	Correct	1 ms	620 KB	Output is correct
12	Correct	1 ms	620 KB	Output is correct
13	Correct	1 ms	620 KB	Output is correct
14	Correct	1 ms	620 KB	Output is correct
15	Correct	1 ms	620 KB	Output is correct
16	Correct	1 ms	620 KB	Output is correct
17	Correct	1 ms	620 KB	Output is correct
18	Correct	1 ms	748 KB	Output is correct
19	Correct	1 ms	620 KB	Output is correct
20	Correct	1 ms	620 KB	Output is correct
21	Correct	2 ms	748 KB	Output is correct
22	Correct	1 ms	748 KB	Output is correct
23	Correct	1 ms	876 KB	Output is correct
24	Correct	1 ms	748 KB	Output is correct
25	Correct	1 ms	748 KB	Output is correct
26	Correct	1 ms	748 KB	Output is correct
27	Correct	1 ms	748 KB	Output is correct
28	Correct	1 ms	748 KB	Output is correct
29	Correct	2 ms	748 KB	Output is correct
30	Correct	2 ms	748 KB	Output is correct

Subtask #7
29.0 / 29.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	44 ms	5740 KB	Output is correct
2	Correct	36 ms	5868 KB	Output is correct
3	Correct	47 ms	5868 KB	Output is correct
4	Correct	36 ms	5868 KB	Output is correct
5	Correct	36 ms	5868 KB	Output is correct
6	Correct	35 ms	5760 KB	Output is correct
7	Correct	35 ms	5740 KB	Output is correct
8	Correct	39 ms	5996 KB	Output is correct
9	Correct	35 ms	5740 KB	Output is correct
10	Correct	35 ms	5740 KB	Output is correct
11	Correct	24 ms	4204 KB	Output is correct
12	Correct	24 ms	4076 KB	Output is correct
13	Correct	26 ms	4076 KB	Output is correct
14	Correct	29 ms	4076 KB	Output is correct
15	Correct	43 ms	5740 KB	Output is correct
16	Correct	24 ms	4076 KB	Output is correct
17	Correct	24 ms	4076 KB	Output is correct
18	Correct	45 ms	5868 KB	Output is correct
19	Correct	36 ms	5868 KB	Output is correct
20	Correct	30 ms	4204 KB	Output is correct
21	Correct	107 ms	13444 KB	Output is correct
22	Correct	102 ms	13284 KB	Output is correct
23	Correct	105 ms	13412 KB	Output is correct
24	Correct	104 ms	13284 KB	Output is correct
25	Correct	109 ms	13412 KB	Output is correct
26	Correct	106 ms	13412 KB	Output is correct
27	Correct	97 ms	13412 KB	Output is correct
28	Correct	96 ms	13412 KB	Output is correct
29	Correct	102 ms	13540 KB	Output is correct
30	Correct	127 ms	13540 KB	Output is correct
31	Correct	1 ms	620 KB	Output is correct
32	Correct	1 ms	620 KB	Output is correct
33	Correct	1 ms	620 KB	Output is correct
34	Correct	1 ms	620 KB	Output is correct
35	Correct	1 ms	620 KB	Output is correct
36	Correct	1 ms	620 KB	Output is correct
37	Correct	1 ms	620 KB	Output is correct
38	Correct	1 ms	620 KB	Output is correct
39	Correct	1 ms	620 KB	Output is correct
40	Correct	1 ms	620 KB	Output is correct
41	Correct	1 ms	620 KB	Output is correct
42	Correct	1 ms	620 KB	Output is correct
43	Correct	1 ms	620 KB	Output is correct
44	Correct	1 ms	620 KB	Output is correct
45	Correct	1 ms	620 KB	Output is correct
46	Correct	1 ms	620 KB	Output is correct
47	Correct	1 ms	620 KB	Output is correct
48	Correct	1 ms	748 KB	Output is correct
49	Correct	1 ms	620 KB	Output is correct
50	Correct	1 ms	620 KB	Output is correct
51	Correct	2 ms	748 KB	Output is correct
52	Correct	1 ms	748 KB	Output is correct
53	Correct	1 ms	876 KB	Output is correct
54	Correct	1 ms	748 KB	Output is correct
55	Correct	1 ms	748 KB	Output is correct
56	Correct	1 ms	748 KB	Output is correct
57	Correct	1 ms	748 KB	Output is correct
58	Correct	1 ms	748 KB	Output is correct
59	Correct	2 ms	748 KB	Output is correct
60	Correct	2 ms	748 KB	Output is correct
61	Correct	68 ms	13284 KB	Output is correct
62	Correct	59 ms	13540 KB	Output is correct
63	Correct	92 ms	13496 KB	Output is correct
64	Correct	58 ms	13412 KB	Output is correct
65	Correct	66 ms	13432 KB	Output is correct
66	Correct	69 ms	13412 KB	Output is correct
67	Correct	82 ms	13284 KB	Output is correct
68	Correct	97 ms	13412 KB	Output is correct
69	Correct	92 ms	13304 KB	Output is correct
70	Correct	92 ms	13284 KB	Output is correct

Submission #336427

Compilation message

Subtask #1 4.0 / 4.0

Subtask #2 8.0 / 8.0

Subtask #3 18.0 / 18.0

Subtask #4 10.0 / 10.0

Subtask #5 11.0 / 11.0

Subtask #6 20.0 / 20.0

Subtask #7 29.0 / 29.0

Subtask #1
4.0 / 4.0

Subtask #2
8.0 / 8.0

Subtask #3
18.0 / 18.0

Subtask #4
10.0 / 10.0

Subtask #5
11.0 / 11.0

Subtask #6
20.0 / 20.0

Subtask #7
29.0 / 29.0