oj.uz

Submission #634036

# Submission time Handle Problem Language Result Execution time Memory
634036 2022-08-23T17:48:02 Z izanbf Hacker (BOI15_hac) C++14
40 / 100
 1000 ms 2796 KB 
#include <bits/stdc++.h>
using namespace std;

#define D(x) cerr << #x << " = " << x << ", "

using vi = vector<int>;
using vvi = vector<vi>;

struct SparseTable {
	const int J = 20;
	const int OP_NULL = 1.01e9;
	vvi st;
	vi lg;
	int n;

	int op(int a, int b) const { return min(a, b); }

	int query(int l, int r) const {
		if (l > r or l < 0 or r >= n)
			return OP_NULL;
		int j = lg[r-l+1];
		return op(st[j][l], st[j][r-(1<<j)+1]);
	}

	SparseTable(const vi& a) {
		n = a.size();
		lg = vi(n+1);
		lg[1] = 0;
		for (int i = 2; i <= n; ++i)
			lg[i] = 1 + lg[i/2];
		st = vvi(J, vi(n));
		for (int i = 0; i < n; ++i)
			st[0][i] = a[i];
		for (int j = 1; j < J; ++j)
			for (int i = 0; i+(1<<j)-1 < n; ++i)
				st[j][i] = op(st[j-1][i], st[j-1][i+(1<<(j-1))]);
	}
};

vi compute_ksums(const vi& a, int k) {
	int n = a.size();
	vi v(2*n);
	for (int i = 0; i < n; ++i) {
		v[i] = v[n+i] = a[i];
	}
	vi pre(2*n+1); // pre[i+1] = v[0]+...+v[i]
	for (int i = 0; i < 2*n; ++i) {
		pre[i+1] = pre[i] + v[i];
	}
	vi ksums(n); // ksums[i] = v[i] + ... + v[i+k-1]
	for (int i = 0; i < n; ++i) {
		ksums[i] = pre[i+k] - pre[i];
	}
	return ksums;
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	cin >> n;

	int k = n/2; // range of the deffender

	int sum = 0;
	vi v(n);
	for (int i = 0; i < n; ++i) {
		cin >> v[i];
		sum += v[i];
	}

	vi ksums = compute_ksums(v, k);
	reverse(v.begin(), v.end());
	vi rev_ksums = compute_ksums(v, k);

	/*SparseTable st(ksums);
	SparseTable rst(rev_ksums);
	int ans = 0;
	for (int i = 0; i < n; ++i) {
		int best = max(st.query(i+1, n+i-k), rst.query(n-1-(n+i-k), n-1-(i+1)));
		ans = max(ans, sum-best);
	}*/

	int ans = 0;
	for (int i = 0; i < n; ++i) {
		int best = 0;
		for (int j = 0; j < n; ++j) {
			int l = j;
			int r = j+k-1;
			if ((i < l or i > r) and (n+i < l or n+i > r)) {
				best = max(best, ksums[j]);
			}
		}
		ans = max(ans, sum-best);
	}

	cout << ans << endl;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 316 KB Output is correct
13 Correct 1 ms 320 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 316 KB Output is correct
13 Correct 1 ms 320 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 3 ms 340 KB Output is correct
21 Correct 2 ms 340 KB Output is correct
22 Correct 12 ms 424 KB Output is correct
23 Correct 36 ms 460 KB Output is correct
24 Correct 12 ms 420 KB Output is correct
25 Correct 44 ms 460 KB Output is correct
26 Correct 30 ms 468 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 1 ms 212 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 32 ms 460 KB Output is correct
31 Correct 32 ms 340 KB Output is correct

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 33 ms 364 KB Output is correct
4 Execution timed out 1074 ms 2796 KB Time limit exceeded
5 Halted 0 ms 0 KB -

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 316 KB Output is correct
13 Correct 1 ms 320 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 3 ms 340 KB Output is correct
21 Correct 2 ms 340 KB Output is correct
22 Correct 12 ms 424 KB Output is correct
23 Correct 36 ms 460 KB Output is correct
24 Correct 12 ms 420 KB Output is correct
25 Correct 44 ms 460 KB Output is correct
26 Correct 30 ms 468 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 1 ms 212 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 32 ms 460 KB Output is correct
31 Correct 32 ms 340 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 1 ms 212 KB Output is correct
34 Correct 33 ms 364 KB Output is correct
35 Execution timed out 1074 ms 2796 KB Time limit exceeded
36 Halted 0 ms 0 KB -