Submission #739796

#	Time	Username	Problem	Language	Result	Execution time	Memory
739796		NeroZein	Feast (NOI19_feast)	C++17	100 / 100	148 ms	13964 KiB

feast

#include "bits/stdc++.h"
using namespace std;
 
#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif
 
const int N = 300005;
 
int n, k;
int a[N];
pair<long long,int> dp[N][2];
pair<long long,int> solve (long long cost) {
	dp[0][0] = {0LL, 0};
	dp[0][1] = {-1e15, -N};
	for (int i = 1; i <= n; ++i) {
		dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
		dp[i][1] = max(make_pair(dp[i - 1][0].first + a[i] - cost, dp[i - 1][0].second + 1), 
									 make_pair(dp[i - 1][1].first + a[i], dp[i - 1][1].second)); 
	}
	return max(dp[n][0], dp[n][1]); 
}
 
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n >> k;
	for (int i = 1; i <= n; ++i) {
		cin >> a[i];
	}
	long long l = 0, r = (long long) N * 1e9;
	while (l < r) {
		long long mid = (l + r) >> 1;
		if (solve(mid).second >= k) {
			l = mid + 1;
		} else {
			r = mid;
		}
	}
	if (solve(l - 1).second == k) {
      cout << solve(l - 1).first + (l - 1) * k << '\n';
    } else {
      cout << solve(l).first + l * k << '\n';
    }
	return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29