Submission #210618

#	Time	Username	Problem	Language	Result	Execution time	Memory
210618		tri	Cake 3 (JOI19_cake3)	C++14	24 / 100	4103 ms	195336 KiB

cake3

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;

#define pb push_back
#define f first
#define s second

const int MAXN = 2e5 + 100;
const int LOGN = 20;
const ll INF = 1e15;
int N, K;

ll v[MAXN], c[MAXN];

ll bTotal = -INF;

set<pl> sets[LOGN];
set<pl> ext[LOGN];
pi sRange[LOGN];
ll sSum[LOGN];

//struct lazyQueue{
//    int
//};

void reRange(int setI, pi nRange) {
//    ps(setI, nRange);
    set<pl> &cSet = sets[setI];
    set<pl> &cExt = ext[setI];
    pi &cRange = sRange[setI];
    ll &cSum = sSum[setI];

//    assert(cRange.f <= nRange.f && cRange.s <= nRange.s);
//    ps(cRange, nRange);

    while (cRange.s < nRange.s) {
        cExt.insert({v[cRange.s + 1], cRange.s + 1});
        cRange.s++;
    }

    while (cRange.f < nRange.f) {
        if (cSet.erase({v[cRange.f], cRange.f})) {
            cSum -= v[cRange.f];
        } else {
            cExt.erase({v[cRange.f], cRange.f});
        }
        cRange.f++;
    }

    while (cSet.size() < K && cExt.size()) {
        cSum += (--cExt.end())->f;

        cSet.insert(*(--cExt.end()));
        cExt.erase(--cExt.end());
    }

    while (cExt.size() && cSet.begin()->f < (--cExt.end())->f) {
        cSum -= cSet.begin()->f;
        cSum += (--cExt.end())->f;

        cExt.insert(*cSet.begin());
        cSet.erase(cSet.begin());

        cSet.insert(*(--cExt.end()));
        cExt.erase(--cExt.end());
    }

//    assert(cRange == nRange);
//    assert(cSet.size() == min(K, cRange.s - cRange.f + 1));
}

ll getTotal(int setI) {
    set<pl> &cSet = sets[setI];
//    assert(cSet.size() <= K);
    if (cSet.size() == K) {
        return sSum[setI];
    } else {
        return -INF;
    }
}

int call = 0;

void compute(int level, int l1, int l2, int r1, int r2) {
    int cL = (l1 + l2) / 2;
//    cout << call++ << endl;

    ll maxTotal = -INF;
    int maxR = -1;

//    assert(0 <= l1 && 0 <= r1);
    for (int cR = max(cL + K - 1, r1); cR <= r2; cR++) {
        reRange(level, {cL, cR});
        ll cTotal = getTotal(level) + c[cL] - c[cR];
        if (cTotal > maxTotal) {
            maxTotal = cTotal;
            maxR = cR;
        }
    }
//    assert(maxR != -1);
    bTotal = max(bTotal, maxTotal);

    if (l1 < cL) {
        compute(level + 1, l1, cL - 1, r1, maxR);
    }
    if (cL < l2) {
        compute(level + 1, cL + 1, l2, maxR, r2);
    }
}

pi items[MAXN];

int main() {
//    freopen("cake3.in", "r", stdin);

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> N >> K;

//    cout << "start" << endl;

    for (int i = 0; i < N; i++) {
        int x, y;
        cin >> x >> y;
        items[i] = {y, x};
    }

    sort(items, items + N);

    for (int i = 0; i < N; i++) {
        v[i] = items[i].s;
        c[i] = items[i].f;
        c[i] *= 2;
    }

    fill(sSum, sSum + LOGN, 0);
    fill(sRange, sRange + LOGN, make_pair(0, -1));

//    cout << "computing" << endl;

    compute(0, 0, N - K, 0, N - 1);
    cout << bTotal << endl;
}

Compilation message (stderr)

cake3.cpp: In function 'void reRange(int, pi)':
cake3.cpp:60:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while (cSet.size() < K && cExt.size()) {
            ~~~~~~~~~~~~^~~
cake3.cpp: In function 'll getTotal(int)':
cake3.cpp:85:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     if (cSet.size() == K) {
         ~~~~~~~~~~~~^~~~

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