Submission #1173222

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173222		totoro	Feast (NOI19_feast)	C++20	100 / 100	177 ms	10920 KiB

feast

#include <array>
#include <iostream>
#include <tuple>
#include <vector>

int main() {
    int n, k;
    std::cin >> n >> k;
    std::vector<int> v(n);
    for (int& i : v) std::cin >> i;
    long long lo = 0, hi = 1e15;
    long long score = 0, amount = 0;
    while (lo < hi) {
        long long m = (lo + hi) / 2;
        std::vector<std::array<std::pair<long long, int>, 2>> dp(n + 1);
        dp[0][1].first = -1e18;
        for (int i = 1; i <= n; ++i) {
            dp[i][1] = dp[i - 1][1];
            if (dp[i - 1][0].first - m > dp[i][1].first || (dp[i - 1][0].first + m == dp[i][1].first && dp[i - 1][0].second + 1 < dp[i][1].second)) {
                dp[i][1] = dp[i - 1][0];
                dp[i][1].first -= m;
                ++dp[i][1].second;
            }
            dp[i][1].first += v[i - 1];
            dp[i][0] = dp[i - 1][0];
            if (dp[i - 1][1].first > dp[i][0].first || (dp[i - 1][1].first == dp[i][0].first && dp[i - 1][1].second < dp[i][0].second)) {
                dp[i][0] = dp[i - 1][1];
            }
        }
        std::pair<long long, int> max = dp[n][0];
        if (dp[n][1].first > max.first || (dp[n][1].first == max.first && dp[n][1].second < max.second)) max = dp[n][1];
        if (max.second > k) {
            lo = m + 1;
        } else {
            hi = m;
            std::tie(score, amount) = max;
        }
    }
    std::cout << score + (amount * lo) << '\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