Submission #420438

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
420438	2021-06-08T11:13:10 Z	MetalPower	Cigle (COI21_cigle)	C++14	100 / 100	623 ms	67388 KB

cigle

#include <bits/stdc++.h>
using namespace std;

const int MX = 5005;

void chmax(int& a, int b){
	if(b > a) a = b;
}

int N, arr[MX], dp[MX][MX];

// Observation #1 : We can easily solve this in O(N^3)
	// dp(i, j) is the largest beauty of the wall if the highest row includes [i, j]
	// the transition is we add another row [j + 1, k] for every j + 1 <= k <= N
	// calculating is easy two pointer

// Observation #2 : if the size of row[j + 1, k] is higher than row[i, j]
	// then for every other k >= current_k 
	// the value of the dp is constant
	// this is also correct for the opposite
	
// So we can solve this in O(N^2) by precomputing the transitions for every j
	// and using two pointer to increment k and decrement i

struct segtree{
	int v[MX * 2];

	void build(int p){
		for(int i = MX; i < 2 * MX; i++) v[i] = dp[i - MX][p];
		for(int i = MX - 1; i > 0; i--) v[i] = max(v[i << 1], v[i << 1 | 1]);
	}

	int range(int l, int r){ // [l, r]
		int res = 0;
		for(l += MX, r += MX + 1; l < r; l >>= 1, r >>= 1){
			if(l & 1) chmax(res, v[l++]);
			if(r & 1) chmax(res, v[--r]);
		}
		return res;
	}
} st;

int main(){
	ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL);

	cin >> N;

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

	for(int p = 0; p < N; p++){
		int i = p, k = p + 1, cnt = -1, bot = 0, top = 0;

		st.build(p);

		while(i >= 0 && k < N){
			if(bot == top){
				cnt++; chmax(dp[p + 1][k], st.range(0, i) + cnt);
				bot += arr[i--]; top += arr[k++];
			}else if(bot < top){
				bot += arr[i--];
			}else if(top < bot){
				top += arr[k++];
			}
		}

		for(int j = p + 1; j < N; j++) chmax(dp[p + 1][j], dp[p + 1][j - 1]);
	}

	int ans = 0;

	for(int p = 0; p < N; p++) chmax(ans, dp[p][N - 1]);

	cout << ans << '\n';
}

Subtask #1
9.0 / 9.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	4 ms	640 KB	Output is correct
2	Correct	4 ms	588 KB	Output is correct
3	Correct	4 ms	540 KB	Output is correct
4	Correct	4 ms	588 KB	Output is correct
5	Correct	5 ms	588 KB	Output is correct
6	Correct	4 ms	588 KB	Output is correct
7	Correct	4 ms	460 KB	Output is correct
8	Correct	5 ms	588 KB	Output is correct
9	Correct	4 ms	588 KB	Output is correct

Subtask #2
11.0 / 11.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	4 ms	640 KB	Output is correct
2	Correct	4 ms	588 KB	Output is correct
3	Correct	4 ms	540 KB	Output is correct
4	Correct	4 ms	588 KB	Output is correct
5	Correct	5 ms	588 KB	Output is correct
6	Correct	4 ms	588 KB	Output is correct
7	Correct	4 ms	460 KB	Output is correct
8	Correct	5 ms	588 KB	Output is correct
9	Correct	4 ms	588 KB	Output is correct
10	Correct	9 ms	844 KB	Output is correct
11	Correct	10 ms	840 KB	Output is correct
12	Correct	8 ms	744 KB	Output is correct
13	Correct	8 ms	844 KB	Output is correct
14	Correct	8 ms	848 KB	Output is correct
15	Correct	8 ms	844 KB	Output is correct
16	Correct	7 ms	588 KB	Output is correct
17	Correct	9 ms	796 KB	Output is correct
18	Correct	8 ms	844 KB	Output is correct
19	Correct	9 ms	716 KB	Output is correct
20	Correct	9 ms	744 KB	Output is correct

Subtask #3
13.0 / 13.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	31 ms	2940 KB	Output is correct
2	Correct	37 ms	3012 KB	Output is correct
3	Correct	37 ms	2988 KB	Output is correct
4	Correct	31 ms	3012 KB	Output is correct
5	Correct	32 ms	3008 KB	Output is correct
6	Correct	32 ms	3000 KB	Output is correct
7	Correct	32 ms	2932 KB	Output is correct
8	Correct	37 ms	2908 KB	Output is correct
9	Correct	33 ms	3012 KB	Output is correct
10	Correct	31 ms	2972 KB	Output is correct
11	Correct	39 ms	2988 KB	Output is correct
12	Correct	34 ms	2944 KB	Output is correct

Subtask #4
15.0 / 15.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	4 ms	640 KB	Output is correct
2	Correct	4 ms	588 KB	Output is correct
3	Correct	4 ms	540 KB	Output is correct
4	Correct	4 ms	588 KB	Output is correct
5	Correct	5 ms	588 KB	Output is correct
6	Correct	4 ms	588 KB	Output is correct
7	Correct	4 ms	460 KB	Output is correct
8	Correct	5 ms	588 KB	Output is correct
9	Correct	4 ms	588 KB	Output is correct
10	Correct	9 ms	844 KB	Output is correct
11	Correct	10 ms	840 KB	Output is correct
12	Correct	8 ms	744 KB	Output is correct
13	Correct	8 ms	844 KB	Output is correct
14	Correct	8 ms	848 KB	Output is correct
15	Correct	8 ms	844 KB	Output is correct
16	Correct	7 ms	588 KB	Output is correct
17	Correct	9 ms	796 KB	Output is correct
18	Correct	8 ms	844 KB	Output is correct
19	Correct	9 ms	716 KB	Output is correct
20	Correct	9 ms	744 KB	Output is correct
21	Correct	31 ms	2940 KB	Output is correct
22	Correct	37 ms	3012 KB	Output is correct
23	Correct	37 ms	2988 KB	Output is correct
24	Correct	31 ms	3012 KB	Output is correct
25	Correct	32 ms	3008 KB	Output is correct
26	Correct	32 ms	3000 KB	Output is correct
27	Correct	32 ms	2932 KB	Output is correct
28	Correct	37 ms	2908 KB	Output is correct
29	Correct	33 ms	3012 KB	Output is correct
30	Correct	31 ms	2972 KB	Output is correct
31	Correct	39 ms	2988 KB	Output is correct
32	Correct	34 ms	2944 KB	Output is correct
33	Correct	31 ms	2908 KB	Output is correct
34	Correct	32 ms	2972 KB	Output is correct
35	Correct	31 ms	2984 KB	Output is correct
36	Correct	32 ms	3004 KB	Output is correct
37	Correct	32 ms	2972 KB	Output is correct
38	Correct	34 ms	2884 KB	Output is correct
39	Correct	37 ms	2992 KB	Output is correct
40	Correct	30 ms	2232 KB	Output is correct
41	Correct	32 ms	2924 KB	Output is correct
42	Correct	30 ms	2980 KB	Output is correct
43	Correct	30 ms	2924 KB	Output is correct
44	Correct	30 ms	2380 KB	Output is correct
45	Correct	30 ms	2820 KB	Output is correct
46	Correct	31 ms	2792 KB	Output is correct
47	Correct	31 ms	2904 KB	Output is correct
48	Correct	31 ms	2800 KB	Output is correct
49	Correct	31 ms	2884 KB	Output is correct

Subtask #5
52.0 / 52.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	4 ms	640 KB	Output is correct
2	Correct	4 ms	588 KB	Output is correct
3	Correct	4 ms	540 KB	Output is correct
4	Correct	4 ms	588 KB	Output is correct
5	Correct	5 ms	588 KB	Output is correct
6	Correct	4 ms	588 KB	Output is correct
7	Correct	4 ms	460 KB	Output is correct
8	Correct	5 ms	588 KB	Output is correct
9	Correct	4 ms	588 KB	Output is correct
10	Correct	9 ms	844 KB	Output is correct
11	Correct	10 ms	840 KB	Output is correct
12	Correct	8 ms	744 KB	Output is correct
13	Correct	8 ms	844 KB	Output is correct
14	Correct	8 ms	848 KB	Output is correct
15	Correct	8 ms	844 KB	Output is correct
16	Correct	7 ms	588 KB	Output is correct
17	Correct	9 ms	796 KB	Output is correct
18	Correct	8 ms	844 KB	Output is correct
19	Correct	9 ms	716 KB	Output is correct
20	Correct	9 ms	744 KB	Output is correct
21	Correct	31 ms	2940 KB	Output is correct
22	Correct	37 ms	3012 KB	Output is correct
23	Correct	37 ms	2988 KB	Output is correct
24	Correct	31 ms	3012 KB	Output is correct
25	Correct	32 ms	3008 KB	Output is correct
26	Correct	32 ms	3000 KB	Output is correct
27	Correct	32 ms	2932 KB	Output is correct
28	Correct	37 ms	2908 KB	Output is correct
29	Correct	33 ms	3012 KB	Output is correct
30	Correct	31 ms	2972 KB	Output is correct
31	Correct	39 ms	2988 KB	Output is correct
32	Correct	34 ms	2944 KB	Output is correct
33	Correct	31 ms	2908 KB	Output is correct
34	Correct	32 ms	2972 KB	Output is correct
35	Correct	31 ms	2984 KB	Output is correct
36	Correct	32 ms	3004 KB	Output is correct
37	Correct	32 ms	2972 KB	Output is correct
38	Correct	34 ms	2884 KB	Output is correct
39	Correct	37 ms	2992 KB	Output is correct
40	Correct	30 ms	2232 KB	Output is correct
41	Correct	32 ms	2924 KB	Output is correct
42	Correct	30 ms	2980 KB	Output is correct
43	Correct	30 ms	2924 KB	Output is correct
44	Correct	30 ms	2380 KB	Output is correct
45	Correct	30 ms	2820 KB	Output is correct
46	Correct	31 ms	2792 KB	Output is correct
47	Correct	31 ms	2904 KB	Output is correct
48	Correct	31 ms	2800 KB	Output is correct
49	Correct	31 ms	2884 KB	Output is correct
50	Correct	505 ms	67268 KB	Output is correct
51	Correct	502 ms	67388 KB	Output is correct
52	Correct	530 ms	67208 KB	Output is correct
53	Correct	519 ms	67276 KB	Output is correct
54	Correct	557 ms	67288 KB	Output is correct
55	Correct	564 ms	67288 KB	Output is correct
56	Correct	623 ms	67264 KB	Output is correct
57	Correct	595 ms	67284 KB	Output is correct
58	Correct	473 ms	67300 KB	Output is correct
59	Correct	418 ms	67012 KB	Output is correct
60	Correct	402 ms	66348 KB	Output is correct
61	Correct	376 ms	67212 KB	Output is correct
62	Correct	375 ms	67144 KB	Output is correct
63	Correct	363 ms	66944 KB	Output is correct
64	Correct	380 ms	67136 KB	Output is correct
65	Correct	373 ms	66932 KB	Output is correct
66	Correct	411 ms	66728 KB	Output is correct
67	Correct	367 ms	66500 KB	Output is correct
68	Correct	373 ms	66436 KB	Output is correct
69	Correct	372 ms	66364 KB	Output is correct
70	Correct	432 ms	66468 KB	Output is correct
71	Correct	418 ms	67072 KB	Output is correct
72	Correct	387 ms	67088 KB	Output is correct

Submission #420438

Compilation message

Subtask #1 9.0 / 9.0

Subtask #2 11.0 / 11.0

Subtask #3 13.0 / 13.0

Subtask #4 15.0 / 15.0

Subtask #5 52.0 / 52.0

Subtask #1
9.0 / 9.0

Subtask #2
11.0 / 11.0

Subtask #3
13.0 / 13.0

Subtask #4
15.0 / 15.0

Subtask #5
52.0 / 52.0