Submission #366991

#	Time	Username	Problem	Language	Result	Execution time	Memory
366991		534351	Feast (NOI19_feast)	C++17	100 / 100	139 ms	12908 KiB

feast

#include <bits/stdc++.h>

using namespace std;

template<class T, class U>
void ckmin(T &a, U b)
{
    if (a > b) a = b;
}

template<class T, class U>
void ckmax(T &a, U b)
{
    if (a < b) a = b;
}

#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define SZ(x) ((int) (x).size())
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)

const int MAXN = 3e5 + 13;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;

int N, K;
ll arr[MAXN], pref[MAXN];
ll dp[MAXN], num[MAXN];

void check(ll P) //penalty P
{
    int best = 0; ll bestval = 0;
    dp[0] = 0;
    num[0] = 0;
    FOR(i, 0, N)
    {
        dp[i + 1] = dp[i];
        num[i + 1] = num[i];
        //or you do like k...i
        ll cur = bestval + pref[i + 1] - P;
        if (cur > dp[i + 1])
        {
            dp[i + 1] = cur;
            num[i + 1] = num[best] + 1;
        }
        if (dp[i + 1] - pref[i + 1] > bestval)
        {
            bestval = dp[i + 1] - pref[i + 1];
            best = i + 1;
        }
    }
}

int32_t main()
{
    cout << fixed << setprecision(12);
    cerr << fixed << setprecision(4);
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> N >> K;
    FOR(i, 0, N)
    {
        cin >> arr[i];
        pref[i + 1] = pref[i] + arr[i];
    }
    ll lo = 0, hi = 4e14;
    while(hi > lo)
    {
        ll mid = (hi + lo) >> 1;
        check(mid);
        if (num[N] > K) lo = mid + 1;
        else hi = mid;
    }
    check(lo);
    cout << dp[N] + lo * num[N] << '\n';
    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