Submission #1117544

#	Time	Username	Problem	Language	Result	Execution time	Memory
1117544		vjudge1	Feast (NOI19_feast)	C++14	100 / 100	120 ms	14020 KiB

feast

#include <bits/stdc++.h>

using ll = long long;
using namespace std;

template<typename T> void umax(T &a, const T b) {a = max(a, b);}
template<typename T> void umin(T &a, const T b) {a = min(a, b);}

constexpr int MAXN = 3e5 + 1;
int N, K;
int A[MAXN];
pair<ll, ll> dp[MAXN][2];

pair<ll, ll> solve(ll mid) {
  dp[0][0] = {0, 0};
  dp[0][1] = {A[0] - mid, 1};
  for (int i = 1; i < N; ++i) {
    dp[i][0] = max(dp[i-1][0], dp[i-1][1]);
    dp[i][1] = max(
        make_pair(dp[i-1][0].first - mid + A[i], dp[i-1][0].second + 1),
        make_pair(dp[i-1][1].first + A[i], dp[i-1][1].second)
        );
  }
  return max(dp[N-1][0], dp[N-1][1]);
}

int main() {
  cin.tie(0)->sync_with_stdio(false);
  cin >> N >> K;
  for (int i = 0; i < N; ++i) cin >> A[i]; 
  ll l = 0, r = 1e18;
  while (l < r) {
    ll mid = (l + r + 1) >> 1;
    if (solve(mid).second >= K) l = mid;
    else r = mid - 1;
  }
  cout << solve(l).first + K * l;
  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