Submission #990888

#	Time	Username	Problem	Language	Result	Execution time	Memory
990888		ToniB	Bigger segments (IZhO19_segments)	C++17	0 / 100	0 ms	344 KiB

segments

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

const int N = 3005;
typedef long long ll;

int n, a[N], dp[N][N];
ll pre[N];

ll sum(int i, int j) {
	if (i) return pre[j] - pre[i - 1];
	return pre[j];
}

int main(){
	cin >> n;
	for (int i = 0; i < n; ++i) cin >> a[i];
	
	pre[0] = a[0];
	for (int i = 1; i < n; ++i) pre[i] = a[i] + pre[i - 1];
	
	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < n; ++j) dp[i][j] = -1e9;
	}
	
	for (int i = 0; i < n; ++i) {
		dp[0][i] = 1;
	}
	
	for (int i = 1; i < n; ++i) {
		for (int j = i; j < n; ++j) {
			int lo = 0, hi = i;
			while (lo < hi) {
				int mid = (lo + hi + 1) >> 1;
				if (sum(i, j) >= sum(mid, i - 1)) lo = mid;
				else hi = mid - 1;
			}
			// dp[i][j] = max(dp[i][j], dp[>= lo][i - 1] + 1)
			for (int k = lo; k < i; ++k) {
				if (sum(i, j) >= sum(k, i - 1)) dp[i][j] = max(dp[i][j], dp[k][i - 1] + 1);
			}
		}
	}
	
	int ans = 0;
	for (int i = 0; i < n; ++i) ans = max(ans, dp[i][n - 1]);

	cout << ans << "\n";
	
	return 0;
}

• Subtask 1: 0 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27