Submission #413979

#	Time	Username	Problem	Language	Result	Execution time	Memory
413979		usachevd0	Meetings (IOI18_meetings)	C++14	100 / 100	3483 ms	361888 KiB

meetings

#include <bits/stdc++.h>
#ifndef LOCAL
    #include "meetings.h"
#endif

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define Time (clock() * 1.0 / CLOCKS_PER_SEC)
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
    return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
    return y > x ? (x = y, true) : false;
}
void debug_out() {
    cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
    cerr << ' ' << A;
    debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
    for (int i = 0; i < n; ++i)
        cerr << a[i] << ' ';
    cerr << endl;
}
#ifdef LOCAL
    #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
    #define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
    #define debug(...) 1337
    #define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
    for (auto& x : v)
        stream << x << ' ';
    return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
    return stream << p.first << ' ' << p.second;
}

template<typename T> ostream& operator << (ostream& stream, const deque<T>& v) {
    for (auto& x : v)
        stream << x << ' ';
    return stream;
}

#ifdef LOCAL
    mt19937 rng(1337);
#else
    mt19937 rng(2122);
#endif
const int INF32 = 1e9;
const ll INF64 = 1e18;
const int maxN = 750005;
int n, Q;
int a[maxN];
int randY[maxN], irandY[maxN];
vector<int> que[maxN];

namespace sgt {
    const int logN = 20;
    const int N = 1 << logN;
    
    pii t[2 * N];
    
    void build() {
        for (int i = 0; i < n; ++i)
            t[i + N] = mp(a[i], randY[i]);
        for (int i = N - 1; i >= 1; --i) {
            t[i] = max(t[i << 1], t[i << 1 | 1]);
        }
    }
    
    int argmax(int l, int r) {
        pii ans = {-INF32, -INF32};
        for (l += N, r += N; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) chkmax(ans, t[l++]);
            if (~r & 1) chkmax(ans, t[r--]);
        }
        return irandY[ans.se];
    }
}


struct line {
    int k;
    ll b;
    
    line() {}
    line(ll _k, ll _b): k(_k), b(_b) {}
    
    ll f(ll x) {
        return k * x + b;
    }
};
ostream& operator << (ostream& stream, const line& l) {
    return stream << l.k << "i + " << l.b;
}
double intersect(const line& lhs, const line& rhs) {
    return (rhs.b - lhs.b) / (double)(lhs.k - rhs.k);
}

namespace treap {
    struct Node {
        int y, sz;
        Node *l, *r;
        
        line e;
        int L;
        
        Node(line _e, int _L) {
            y = rng();
            sz = 1;
            l = r = 0;
            e = _e;
            L = _L;
        }
    };
    
    int sz(Node* t) {
        return t ? t->sz : 0;
    }
    
    void upd(Node* t) {
        if (t) {
            t->sz = sz(t->l) + 1 + sz(t->r);
        }
    }
    
    Node* merge(Node* a, Node* b) {
        if (!a) return b;
        if (!b) return a;
        if (a->y > b->y) {
            a->r = merge(a->r, b);
            upd(a);
            return a;
        } else {
            b->l = merge(a, b->l);
            upd(b);
            return b;
        }
    }
    
    void clear(Node *t) {
        if (!t) return;
        clear(t->l);
        clear(t->r);
        // delete t;
    }
    
    pair<line, int> getLeft(Node *t) {
        assert(t);
        while (t->l)
            t = t->l;
        return {t->e, t->L};
    }
    
    void removeLeft(Node*& t) {
        if (!t) return;
        if (t->l) {
            removeLeft(t->l);
            upd(t);
        } else {
            auto tt = merge(t->l, t->r);
            // delete t;
            t = tt;
        }
    }
    
    void addToAll(Node* t, ll delta) {
        if (!t) return;
        addToAll(t->l, delta);
        t->e.b += delta;
        addToAll(t->r, delta);
    }
    
    ll f(Node *t, int i) {
        ll ans = 0;
        while (t) {
            if (t->L <= i) {
                ans = t->e.f(i);
                t = t->r;
            } else {
                t = t->l;
            }
        }
        return ans;
    }
}

struct DS {
    ll delta;
    treap::Node* T;
    
    int R;
    
    DS() {
        delta = 0;
        T = 0;
    }
    DS(ll x, int l) {
        delta = 0;
        T = new treap::Node({0, x}, l);
    }
    
    void clear() {
        delta = 0;
        treap::clear(T);
        T = 0;
    }
    int size() {
        return treap::sz(T);
    }
    void pushBack(line e, int l) {
        e.b -= delta;
        T = treap::merge(T, new treap::Node(e, l));
    }
    void pushFront(line e, int l) {
        e.b -= delta;
        T = treap::merge(new treap::Node(e, l), T);
    }
    void pushBack(int i, ll x) {
        x -= delta;
        T = treap::merge(T, new treap::Node({0, x}, i));
    }
    void pushFront(int i, ll x) {
        x -= delta;
        T = treap::merge(new treap::Node({0, x}, i), T);
    }
    void add(ll d) {
        delta += d;
    }
    
    void relaxPrefix(line e) {
        /*if (val.empty()) return;
        e.b -= delta;
        if (val[0].f(L[0]) <= e.f(L[0])) return;
        int l = L[0];
        while (!val.empty() && val[0].f(L[0]) > e.f(L[0])) {
            int r = (val.size() > 1 ? L[1] - 1 : R);
            if (val[0].f(r) >= e.f(r)) {
                val.pop_front();
                L.pop_front();
            } else {
                L[0] = ceil(intersect(e, val[0]));
                break;
            }
        }
        val.push_front(e);
        L.push_front(l);*/
        
        if (!T) return; 
        e.b -= delta;   
        line e1;    
        int L1; 
        tie(e1, L1) = treap::getLeft(T);    
        int l = L1; 
        if (e1.f(L1) <= e.f(L1)) return;    
        while (T && e1.f(L1) > e.f(L1)) {   
            treap::removeLeft(T);   
            int r = T ? treap::getLeft(T).se - 1 : R;   
            if (e1.f(r) >= e.f(r)) {    
                if (!T) break;  
                tie(e1, L1) = treap::getLeft(T);    
            } else {    
                T = treap::merge(new treap::Node(e1, ceil(intersect(e, e1))), T);   
                break;  
            }   
        }   
        T = treap::merge(new treap::Node(e, l), T);
    }
    
    ll f(int i) {
        // int t = upper_bound(all(L), i) - L.begin() - 1;
        // if (t < 0) return 0;
        // return val[t].f(i) + delta;
         if (!T || treap::getLeft(T).se > i) return 0;
        return treap::f(T, i) + delta;
    }
};// PP[maxN];

vector<ll> minimum_costs(vector<int> _a, vector<int> ql, vector<int> qr) {
    n = _a.size(), Q = ql.size();
    for (int i = 0; i < n; ++i)
        a[i] = _a[i];
    
    iota(randY, randY + n, 0);
    shuffle(randY, randY + n, rng);
    for (int i = 0; i < n; ++i)
        irandY[randY[i]] = i;
    
    vector<ll> ans(Q, INF64);
    for (int rot = 0; rot < 2; ++rot) {
        for (int i = 0; i < n; ++i) {
            que[i].clear();
            // PP[i].clear();
        }
        sgt::build();
        for (int i = 0; i < Q; ++i) {
            int j = sgt::argmax(ql[i], qr[i]);
            que[j].push_back(i);
        }
        
        function<DS(int, int)> solve = [&](int L, int R) {
            if (L > R) return DS();
            int I = sgt::argmax(L, R);
            ll M = a[I];
            
            // debug(L, I, R);
            
            // auto& P = PP[I];
            // int IL = solve(L, I - 1);
            // auto& PL = PP[IL];
            // int IR = solve(I + 1, R);
            // auto& PR = PP[IR];
            
            DS P;
            P.R = R;
            DS PL = solve(L, I - 1);
            DS PR = solve(I + 1, R);
            
            for (int q : que[I]) {
                int l = ql[q], r = qr[q];
                chkmin(ans[q], PR.f(r) + M * (I - l + 1));
            }
            
            PR.add(M * (I - L + 1));
            PR.relaxPrefix({M, PL.f(I - 1) - M * (I - 1)});
            
            if (PR.size() <= PL.size()) {
                swap(P, PL);
                P.R = R;
                P.pushBack(I, P.f(I - 1) + M);
                
                // for (int i = 0; i < PR.size(); ++i) {
                //     line e = PR.val[i];  
                //     e.b += PR.delta;
                //     int l = PR.L[i];
                //     P.pushBack(e, l);
                // }
                // for (int i = I + 1, t = 0; i <= R; ++i) {
                //     while (t + 1 < PR.size() && PR.L[t + 1] <= i)
                //         ++t;
                //     P.pushBack(i, PR.val[t].f(i) + PR.delta);
                // }
                
                treap::addToAll(PR.T, + PR.delta - P.delta);
                P.T = treap::merge(P.T, PR.T);
                
                PR.clear();
            } else {
                swap(P, PR);
                P.R = R;
                P.pushFront(I, PL.f(I - 1) + M);
                
                // for (int i = (int)PL.size() - 1; i >= 0; --i) {
                //     line e = PL.val[i];
                //     e.b += PL.delta;
                //     int l = PL.L[i];
                //     P.pushFront(e, l);
                // }
                
                // for (int i = I - 1, t = PL.size() - 1; i >= L; --i) {
                //     while (PL.L[t] > i)
                //         --t;
                //     P.pushFront(i, PL.val[t].f(i) + PL.delta);
                // }
                
                treap::addToAll(PL.T, + PL.delta - P.delta);
                P.T = treap::merge(PL.T, P.T);
                
                PL.clear();
            }
            
            // debug(L, I, R);
            // for (int i = L; i <= R; ++i)
            //     cerr << P.f(i) << ' ';
            // cerr << endl;
            
            return P;
            // return I;
        };
        auto P = solve(0, n - 1);
        P.clear();
        
        reverse(a, a + n);
        reverse(randY, randY + n);
        for (int i = 0; i < n; ++i)
            irandY[randY[i]] = i;
        for (int i = 0; i < Q; ++i) {
            ql[i] = n - ql[i] - 1;
            qr[i] = n - qr[i] - 1;
            swap(ql[i], qr[i]);
        }
    }
    return ans;
}



#ifdef LOCAL

int read_int() {
  int x;
  if (scanf("%d", &x) != 1) {
    fprintf(stderr, "Error while reading input\n");
    exit(1);
  }
  return x;
}

int32_t main() {
#ifdef LOCAL
    freopen("in", "r", stdin);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    
    int N = read_int();
  int Q = read_int();
  std::vector<int> H(N);
  for (int i = 0; i < N; ++i) {
    H[i] = read_int();
  }
  std::vector<int> L(Q), R(Q);
  for (int j = 0; j < Q; ++j) {
    L[j] = read_int();
    R[j] = read_int();
  }

  std::vector<long long> C = minimum_costs(H, L, R);
  for (size_t j = 0; j < C.size(); ++j) {
    printf("%lld\n", C[j]);
  }
  return 0;

    return 0;
}
#endif

• Subtask 1: 4 / 4
• Subtask 2: 15 / 15
• Subtask 3: 17 / 17
• Subtask 4: 24 / 24
• Subtask 5: 40 / 40