Submission #669837

#	Time	Username	Problem	Language	Result	Execution time	Memory
669837		Cyanmond	Cigle (COI21_cigle)	C++17	100 / 100	442 ms	98712 KiB

cigle

#include <bits/stdc++.h>

int main() {
    int N;
    std::cin >> N;
    std::vector<int> D(N);
    for (auto &e : D) {
        std::cin >> e;
    }

    std::vector<std::vector<int>> dp(N, std::vector<int>(N));

    for (int s = 1; s < N; ++s) {
        std::vector<int> a, b;
        for (int i = s; i < N; ++i) {
            a.push_back(D[i]);
            if (i != s) {
                a[i - s] += a[i - s - 1];
            }
        }
        for (int i = 0; i < s; ++i) {
            b.push_back(D[s - i - 1]);
            if (i != 0) {
                b[i] += b[i - 1];
            }
        }
        const int t = (int)a.size();

        std::vector<int> points;
        {
            int r = 0;
            for (int i = 0; i < t - 1; ++i) {
                while (r != s and b[r] < a[i]) {
                    ++r;
                }
                if (r < s - 1 and a[i] == b[r]) {
                    points.push_back(a[i]);
                }
            }
        }
        const int m = (int)points.size();

        std::vector<int> max_c(s);
        for (int i = 0; i < s; ++i) {
            max_c[i] = dp[s - 1][i];
            if (i != 0) {
                max_c[i] = std::max(max_c[i], max_c[i - 1]);
            }
        }

        int max_v = 0;
        dp[s][s] = max_c[s - 1];
        int r = 0, count_p = 0;
        for (int i = 1; i < t; ++i) {
            // dp[s + i][s]
            while (count_p != m and points[count_p] <= a[i - 1]) {
                while (r != s - 1 and b[r] < points[count_p]) {
                    max_v = std::max(max_v, dp[s - 1][s - r - 2] + count_p);
                    ++r;
                }
                ++count_p;
            }

            dp[s + i][s] = std::max(max_v, r == s - 1 ? 0 : (max_c[s - r - 2] + count_p));
            /*

            for (int j = 0; j < s - 1; ++j) {
                int v = dp[s - 1][j];
                auto itr = std::upper_bound(points.begin(), points.end(), std::min(a[i - 1], b[s - j - 2]));
                dp[s + i][s] = std::max(dp[s + i][s], v + (int)(itr - points.begin()));
            }
            */
        }
    }

    std::cout << *std::max_element(dp[N - 1].begin(), dp[N - 1].end()) << std::endl;
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 52 / 52