Submission #413885

#	Time	Username	Problem	Language	Result	Execution time	Memory
413885		usachevd0	Meetings (IOI18_meetings)	C++14	60 / 100	3035 ms	786432 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;
}

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(bool rev = false) {
        for (int i = 0; i < n; ++i)
            t[i + N] = (!rev ? mp(a[i], randY[i]) : 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[labs(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);
}

struct DS {
    ll delta;
    deque<line> val;
    deque<int> L;
    
    int R;
    
    DS() {
        delta = 0;
        val.clear();
        L.clear();
    }
    DS(ll x, int l) {
        delta = 0;
        val = {{0, x}};
        L = {l};
    }
    
    void clear() {
        delta = 0;
        val.clear();
        L.clear();
    }
    int size() {
        return val.size();
    }
    void pushBack(int i, ll x) {
        x -= delta;
        val.push_back({0, x});
        L.push_back(i);
    }
    void pushFront(int i, ll x) {
        x -= delta;
        val.push_front({0, x});
        L.push_front(i);
    }
    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);
    }
    
    ll f(int i) {
        // if (val.empty()) return 0;
        int t = upper_bound(all(L), i) - L.begin() - 1;
        if (t < 0) return 0;
        return val[t].f(i) + delta;
    }
};

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];
    
    mt19937 rng(228);
    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(rot);
        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 (R - I <= I - L /*PR.size() <= PL.size()*/) {
                swap(P, PL);
                P.R = R;
                P.pushBack(I, P.f(I - 1) + M);
                
                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);
                }
                PR.clear();
            } else {
                swap(P, PR);
                P.R = R;
                P.pushFront(I, PL.f(I - 1) + M);
                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);
                }
                PL.clear();
            }
            
            // debug(L, I, R);
            // debug(P.val);
            // debug(P.L);
            // for (int i = L; i <= R; ++i)
            //     cerr << P.f(i) << ' ';
            // cerr << endl;
            // debug(ans);
            
            return P;
        };
        auto P = solve(0, n - 1);
        P.clear();
        
        reverse(a, a + n);
        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: 0 / 40