Submission #1025978

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025978		Zicrus	Feast (NOI19_feast)	C++17	12 / 100	123 ms	5700 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];
    ll ps = 0;
    ll psSeg = 1;
    for (int i = 1; i < n; i++) {
        ps = (dp - ps * p) > (dpSeg - psSeg * p) ? ps : psSeg;
        dp = (dp - ps * p) > (dpSeg - psSeg * p) ? dp : dpSeg;
        if (dp - ((ps+1) * p) > dpSeg) {
            dpSeg = dp - p + a[i];
            psSeg = ps + 1;
        }
        else {
            dpSeg += a[i];
        }
    }
    ll val = (dp - ps * p) > (dpSeg - psSeg * p) ? (dp - ps * p) : (dpSeg - psSeg * p);
    ll pss = dp == dpSeg ? min(ps, psSeg) : (dp > dpSeg ? ps : psSeg);
    return {val, pss};
}

int main() {
    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;
    while (l < r) {
        ll mid = (l + r) / 2;
        bestK = solve(mid).second;
        if (bestK > k) {
            l = mid + 1;
        }
        else {
            r = mid;
        }
    }
    auto s = solve(l);
    ll val = solve(l).first + k * l;
    cout << val;
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:49:10: warning: variable 's' set but not used [-Wunused-but-set-variable]
   49 |     auto s = solve(l);
      |          ^

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 0 / 18
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11
• Subtask 6: 0 / 20
• Subtask 7: 0 / 29