Submission #1209941

#	Time	Username	Problem	Language	Result	Execution time	Memory
1209941		quannnguyen2009	Feast (NOI19_feast)	C++20	18 / 100	73 ms	12104 KiB

feast

#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define sz(v) (int)v.size()
#define all(v) v.begin(), v.end()
using namespace std;

const int N = 3e5+5, mod = 1e9+7, inf = 1e18;

int n, k;

int a[N];
ii dp[N][2];

ii solve(int lmb) {
    dp[0][0] = {0, 0};
    dp[0][1] = {a[0]-lmb, 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].fi+a[i]-lmb, dp[i-1][0].se+1), make_pair(dp[i-1][1].fi+a[i], dp[i-1][1].se));
    }
    return max(dp[n-1][0], dp[n-1][1]);
}

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> k;
    for (int i=0; i<n; i++) cin >> a[i];
    int lo = 0, hi = inf, ans = -1;
    while (lo<=hi) {
        int mid = (lo+hi)>>1;
        if (solve(mid).se>=k) {
            ans = mid;
            lo = mid+1;
        } else {
            hi = mid-1;
        }
    }
    cout << solve(ans).fi+ans*k;
}

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