제출 #830826

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
830826		GrindMachine	Feast (NOI19_feast)	C++17	30 / 100	765 ms	17428 KiB

feast

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
http://www.serbanology.com/vault/The%20Trick%20From%20Aliens

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    ll n,k; cin >> n >> k;
    vector<ll> a(n+5);
    rep1(i,n) cin >> a[i];

    vector<ll> pref(n+5);
    rep1(i,n) pref[i] = pref[i-1] + a[i];

    auto get = [&](ld lambda) -> pair<ld,ll>{
        vector<pair<ld,ll>> dp(n+5);
        pair<ld,ll> best = {0,0};

        rep1(i,n){
            // do nothing
            dp[i] = dp[i-1];

            // put in subarray
            pair<ld,ll> px = {pref[i]+best.ff-lambda,best.ss+1};
            amax(dp[i],px);

            px = {-pref[i]+dp[i].ff,dp[i].ss};
            amax(best,px);
        }

        return dp[n];
    };

    ld l = 0, r = inf1*n;
    ld lambda = -1;

    rep(iter,200){
        ld mid = (l+r)/2;
        if(get(mid).ss <= k){
            lambda = mid;
            r = mid;
        }
        else{
            l = mid;
        }
    }

    auto [sum,cnt] = get(lambda);
    ll ans = sum + cnt*lambda;
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

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