제출 #1185250

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1185250		ericl23302	Feast (NOI19_feast)	C++20	100 / 100	451 ms	12328 KiB

feast

#include <iostream>
#include <vector>
#include <algorithm>

#define int long long

using namespace std;

// int code(int oriN, int k, vector<int> &oriVals) {
//     vector<int> vals;
//     int cur = 0;
//     for (int i = 0; i < oriN; ++i) {
//         int temp = oriVals[i];
//         if (cur == 0 || ((temp < 0) && (cur < 0)) || ((temp > 0) && (cur > 0))) cur += temp;
//         else {
//             vals.push_back(cur);
//             cur = temp;
//         }
//     }
//     if (cur) vals.push_back(cur);

//     int newN = vals.size();
//     static int dp[2005][2005][2] = {0};
//     for (int i = 1; i <= newN; ++i) {
//         for (int j = 1; j <= k; ++j) {
//             dp[i][j][1] = max(dp[i - 1][j][1], dp[i - 1][j - 1][0]) + vals[i - 1];
//             dp[i][j][0] = max(dp[i - 1][j][1], dp[i - 1][j][0]);
//         }
//     }

//     if (newN == 1 && max(dp[newN][k][1], dp[newN][k][0]) != vals[0]) return -1;
//     return max(dp[newN][k][1], dp[newN][k][0]);
// }

// int bruteforce(int oriN, int k, vector<int> &oriVals) {
//     int res = 0;
//     for (int &i : oriVals) res += i;
//     return res;
// }

signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int oriN, k; cin >> oriN >> k;
    vector<int> vals;
    int cur = 0;
    for (int i = 0; i < oriN; ++i) {
        int temp; cin >> temp;
        if (cur == 0 || ((temp < 0) && (cur < 0)) || ((temp > 0) && (cur > 0))) cur += temp;
        else {
            vals.push_back(cur);
            cur = temp;
        }
    }
    if (cur) vals.push_back(cur);

    int newN = vals.size();

    auto check = [&](int penalty) {
        vector<vector<pair<int, int>>> dp(newN + 1, vector<pair<int, int>>(2));
        dp[1][0] = {0, 0};
        dp[1][1] = {vals[0] - penalty, 1};
        for (int i = 2; i <= newN; ++i) {
            dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);
            dp[i][1] = max(make_pair(dp[i - 1][0].first + vals[i - 1] - penalty, dp[i - 1][0].second + 1), make_pair(dp[i - 1][1].first + vals[i - 1], dp[i - 1][1].second));
        }
        return max(dp[newN][0], dp[newN][1]);
    };

    int low = 0, high = 1e18;
    while (low < high) {
        int mid = (low + high + 1) / 2;
        if (check(mid).second >= k) low = mid;
        else high = mid - 1;
    }

    cout << (check(low).first + low * k) << '\n';

    // srand(time({}));

    // for (int i = 0; i < 100; ++i) {
    //     cout << "Test: " << i + 1 << '\n';
    //     int n = rand() % 100 + 1, k = rand() % n + 1;
    //     vector<int> oriVals(n);
    //     cout << "n: " << n << "\nk: " << k << '\n';
    //     cout << "Vals: ";
    //     for (int i = 0; i < n; ++i) oriVals[i] = rand() % 100'000, cout << oriVals[i] << ' ';
    //     cout << '\n';
    //     int codeRes = code(n, k, oriVals), bruteforceRes = bruteforce(n, k, oriVals);
    //     if (codeRes == bruteforceRes) cout << "Test Success.\n";
    //     else {
    //         cout << "Test Failed.\n";
    //         cout << "Code: " << codeRes << '\n';
    //         cout << "Bruteforce: " << bruteforceRes << '\n';
    //         break;
    //     }
    // }

    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