Submission #1147318

#	Time	Username	Problem	Language	Result	Execution time	Memory
1147318		Mike_Vu	Cake 3 (JOI19_cake3)	C++17	0 / 100	1 ms	328 KiB

cake3

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double dou;
#define pii pair<int, int>
#define fi first
#define se second
#define pb push_back
#define ALL(v) v.begin(), v.end()
#define BITj(x, j) (((x)>>(j))&1)
#define MASK(x) (1LL<<(x))

template<typename T> bool maximize(T &x, const T &y) {
    if (x < y) {x = y; return 1;}
    return 0;
}
template<typename T> bool minimize(T &x, const T &y) {
    if (x > y) {x = y; return 1;}
    return 0;
}

const int maxn = 2e5+5;
int n, m;
pii a[maxn];
ll ans = LLONG_MIN;

void input() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) {
        cin >> a[i].se >> a[i].fi;
    }
}

namespace sub3{
    struct SMT{
        int trsz;
        vector<ll> tr;
        vector<int> cnt;
        void init(int n) {
            trsz = 1;
            while (trsz < n) trsz <<= 1;
            tr.assign(trsz<<1, 0);
            cnt.assign(trsz<<1, 0);
        }
        void update(int k, int x, int c) {
            k += trsz-1;
            while (k > 0) {
                tr[k] += x*c;
                cnt[k] += c;
                k >>= 1;
            }
        }
        ll walk(int id, int &target) {
            if (target >= cnt[id]) {
                target -= cnt[id];
                return tr[id];
            }
            if (id >= trsz) {
                return 0;
            }
            ll sum = walk(id<<1|1, target);
            if (target > 0) {
                sum += walk(id<<1, target);
            }
            return sum;
        }
        ll query() {
            int temp = m;
            return walk(1, temp);
        }
    };
    vector<int> values;
    SMT tr;
    void discretize() {
        sort(ALL(values));
        values.erase(unique(ALL(values)), values.end());
    }
    int fval(int x) {
        return lower_bound(ALL(values), x)-values.begin()+1;
    }
    void insval(int x) {
        int cor = fval(x);
        tr.update(cor, x, 1);
    }
    void remval(int x) {
        int cor = fval(x);
        tr.update(cor, x, -1);
    }
    void dnc(int l, int r, int opl, int opr) {
        //find best, minimize ans
//        cout << "begin " << l << ' ' << r << "\n";
        int opt = -1, mid = (l+r)>>1;
        ll best = LLONG_MIN;
        for (int i = max(mid, opl); i <= opr; i++) {
            insval(a[i].se);
            ll val = tr.query() - 2LL*(a[i].fi-a[mid].fi);
            if (mid+m-1 <= i && maximize(best, val)) {
                opt = i;
            }
        }
        maximize(ans, best);
        //clear & continue
        int nxtmid;
        if (l < mid) {
            nxtmid = (l+mid-1)>>1;
            for (int i = max(mid, opl); i <= opr; i++) {
                remval(a[i].se);
            }
            for (int i = nxtmid; i < min(opl, mid); i++) {
                insval(a[i].se);
            }
            dnc(l, mid-1, opl, opt);
            for (int i = max(mid, opl); i <= opr; i++) {
                insval(a[i].se);
            }
            for (int i = nxtmid; i < min(opl, mid); i++) {
                remval(a[i].se);
            }
        }
        if (mid < r) {
            nxtmid = (r+mid+1)>>1;
            for (int i = mid; i < nxtmid; i++) {
                remval(a[i].se);
            }
            for (int i = max(nxtmid, opt); i <= opr; i++) {
                remval(a[i].se);
            }
            dnc(mid+1, r, opt, opr);
            for (int i = mid; i < nxtmid; i++) {
                insval(a[i].se);
            }
            for (int i = max(nxtmid, opt); i <= opr; i++) {
                insval(a[i].se);
            }
        }
        //clear & return
        for (int i = max(mid, opl); i <= opr; i++) {
            remval(a[i].se);
        }
//        cout << "end " << l << ' ' << r << "\n";
    }
    void solve() {
        sort(a+1, a+n+1);
        for (int i= 1; i <= n; i++) {
            values.pb(a[i].se);
        }
        discretize();
        tr.init((int)values.size());
        dnc(1, n-m+1, 1, n);
        cout << ans;
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    #define name "task"
    if (fopen(name".inp", "r")) {
        freopen(name".inp", "r", stdin);
        freopen(name".out", "w", stdout);
    }
    input();
    return sub3::solve(), 0;
}
/*
5 3
2 1
4 2
6 4
8 8
10 16

    multiset<int> st1, st2;
    ll cursum = 0;
    void insval(int x) {
//        cout << "insval " << x << "\n";
        st1.insert(x);
        cursum += x;
        while ((int)st1.size() > m) {
            int val = *st1.begin();
            st1.erase(st1.begin());
            cursum -= val;
            st2.insert(val);
        }
    }
    void remval(int x) {
//        cout << "remval " << x << "\n";
        auto it = st1.find(x);
        if (it == st1.end()) st2.erase(st2.find(x));
        else {
            st1.erase(it);
            cursum -= x;
        }
        if (!st2.empty() && (int)st1.size() < m) {
            it = prev(st2.end());
            int val = *it;
            st2.erase(it);
            st1.insert(val);
            cursum += val;
        }
    }
*/

Compilation message (stderr)

cake3.cpp: In function 'int main()':
cake3.cpp:160:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  160 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cake3.cpp:161:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  161 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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