Submission #1026006

#	Time	Username	Problem	Language	Result	Execution time	Memory
1026006		Zicrus	Feast (NOI19_feast)	C++17	100 / 100	106 ms	5724 KiB

feast

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

typedef long long ll;

ll n, k;
vector<ll> a;

pair<ll, ll> solve(ll p) {
    ll dp = 0;
    ll dpSeg = a[0] - p;
    ll ps = 0;
    ll psSeg = 1;
    for (int i = 1; i < n; i++) {
        ll tdp = dp, tdpSeg = dpSeg, tps = ps, tpsSeg = psSeg;
        if (tdpSeg > tdp) {
            dp = tdpSeg;
            ps = tpsSeg;
        }
        if (tdp - p > tdpSeg) {
            dpSeg = tdp - p;
            psSeg = tps + 1;
        }
        dpSeg += a[i];
    }
    if (dpSeg > dp) {
        dp = dpSeg;
        ps = psSeg;
    }
    return {dp, ps};
}

int main() {
    ios::sync_with_stdio(0);

    cin >> n >> k;
    a = vector<ll>(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    ll l = 0, r = 1ll << 50;
    ll bestK = 1ll << 50;
    ll bestAns = 0;
    ll pen = 0;
    while (l <= r) {
        ll mid = pen = (l + r) / 2;
        auto best = solve(mid);
        bestK = best.second;
        bestAns = best.first;

        if (bestK > k) {
            l = mid + 1;
        }
        else {
            if (l == r) break;
            r = mid;
        }
    }
    ll val = bestAns + k * pen;
    cout << val;
}

• 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