Submission #377963

#	Time	Username	Problem	Language	Result	Execution time	Memory
377963		2qbingxuan	Cake 3 (JOI19_cake3)	C++14	24 / 100	4021 ms	8300 KiB

cake3

#include <bits/stdc++.h>
#ifdef local
#define debug(a...) qqbx(#a, a)
template <typename ...T> void qqbx(const char *s, T ...a) {
    int cnt = sizeof...(T);
    ((std::cerr << "\033[1;32m(" << s << ") = (") , ... , (std::cerr << a << (--cnt ? ", " : "\033[0m)\n")));
}
#define safe std::cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
#else
#define debug(...) ((void)0)
#define safe ((void)0)
#endif // local
#define all(v) begin(v),end(v)
#define pb emplace_back
#define sort_uni(v) sort(all(v)), v.erase(unique(all(v)), v.end())

using namespace std;
using ll = int64_t;
template <typename T> using min_heap = priority_queue<T, vector<T>, greater<T>>;
const ll INF = 1e18;
const int maxn = 500025, inf = 1e9;

pair<int,int> v[maxn];

struct Event {
    int l, r, fl, fr;
};

struct kthMaxsum {
    multiset<int> ms;
    void insert(int x) {
        ms.insert(x);
    }
    void erase(int x) {
        ms.erase(ms.find(x));
    }
    ll query(int k) {
        if (ms.size() < k) return -INF;
        ll sum = 0;
        auto it = ms.end();
        for (int i = 0; i < k; i++)
            sum += *--it;
        return sum;
    }
} ds;

int n, k;
void update(int l, int r) { // [l, r]
    static int curL = 1, curR = 0;
    while (curR < r) ds.insert(v[++curR].second);
    while (curL > l) ds.insert(v[--curL].second);
    while (curR > r) ds.erase(v[curR--].second);
    while (curL < l) ds.erase(v[curL++].second);
}
ll res = -INF;
void solve(int l, int r, int fl, int fr) {
    if (l == r) return;
    int m = (l+r)/2;
    ll ans = -INF;
    int pos = -1;
    for (int i = fl; i < fr && i < m; i++) {
        update(i+1, m-1);
        ll cur = ds.query(k) + v[i].second + v[m].second - abs(v[i].first - v[m].first) * 2;
        if (ans < cur) {
            ans = cur;
            pos = i;
        }
    }
    res = max(res, ans);
    solve(l, m, fl, pos+1);
    solve(m+1, r, pos, fr);
}


signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    cin >> n >> k;
    // int seed = time(0);
    // debug(seed);
    // srand(seed);
    // for (int i = 0; i < n; i++) v[i] = {rand() % 10, rand() % 10};
    for (int i = 0; i < n; i++) cin >> v[i].second >> v[i].first;
    sort(v, v+n);

    k -= 2;
    /*
    ll ans = -INF;
    for (int i = 0; i < n; i++) {
        priority_queue<int, vector<int>, greater<int>> pq;
        ll sum = 0;
        for (int j = i+1; j < n; j++) {
            if (pq.size() == k)
                ans = max(ans, sum + v[i].second + v[j].second - (v[j].first - v[i].first) * 2);
            sum += v[j].second, pq.push(v[j].second);
            if (pq.size() > k) sum -= pq.top(), pq.pop();
        }
    }
    cout << ans << '\n';
    */
    solve(k+1, n, 0, n);
    cout << res << '\n';
}

Compilation message (stderr)

cake3.cpp: In member function 'll kthMaxsum::query(int)':
cake3.cpp:38:23: warning: comparison of integer expressions of different signedness: 'std::multiset<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   38 |         if (ms.size() < k) return -INF;
      |             ~~~~~~~~~~^~~

• Subtask 1: 5 / 5
• Subtask 2: 19 / 19
• Subtask 3: 0 / 76