oj.uz

Submission #378003

# Submission time Handle Problem Language Result Execution time Memory
378003 2021-03-15T17:18:58 Z Vimmer 3D Histogram (COCI20_histogram) C++14
110 / 110
 749 ms 41984 KB 
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")

#define N 250051
#define NN 1005000
#define PB push_back
#define M ll(1e9 + 7)
#define all(x) x.begin(), x.end()
#define sz(x) int(x.size())
#define pri(x) cout << x << endl
#define endl '\n'
#define _ << " " <<
#define F first
#define S second

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
//typedef tree <ll, null_type, less_equal <ll>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

typedef long double ld;
typedef unsigned long long ull;
typedef short int si;

ll n, a[N], b[N], pr[N][2], sf[N][2];

vector <pair <ll, ll> > t[N * 4];

ll ans = 0;

ll inter(pair <ll, ll> x, pair <ll, ll> y)
{
    ll k = (y.F - x.F);

    ll b = (x.S - y.S);

    if (k == 0)
    {
        if (b > 0)
            return -1e18;

        return 1e18;
    }

    bool f1 = (k <= 0);

    bool f2 = (b <= 0);

    if (f1 == f2)
        return b / k + bool(b % k);

    return b / k;
}

void bld(ll v, ll tl, ll tr)
{
    t[v].clear();

    ll ps = tl;

    while (ps < tr && pr[ps + 1][0] == pr[tl][0])
        ps++;

    t[v].PB({-pr[ps][0], 1ll * pr[ps][0] * ps});

    for (ll i = ps + 1; i <= tr; i++)
    {
        pair <ll, ll> pt = {-pr[i][0], 1ll * pr[i][0] * i};

        while(sz(t[v]) > 1)
        {
            pair <ll, ll> lst = t[v][sz(t[v]) - 2];

            ll a = inter(lst, t[v].back());

            ll b = inter(lst, pt);

            if (b > a)
                break;

            t[v].pop_back();
        }

        t[v].PB(pt);
    }

    if (tl == tr) return;

    ll md = (tl + tr) >> 1;

    bld(v + v, tl, md);

    bld(v + v + 1, md + 1, tr);
}

ll get(ll v, ll tl, ll tr, ll l, ll r, ll x)
{
    if (tr < l || l > r || r < tl || tl > tr) return 0;

    if (l <= tl && tr <= r)
    {
        while (sz(t[v]) > 1 && inter(t[v].back(), t[v][sz(t[v]) - 2]) > x)
            t[v].pop_back();

        return t[v].back().S + t[v].back().F * x;
    }

    ll md = (tl + tr) >> 1;

    return max(get(v + v, tl, md, l, r, x), get(v + v + 1, md + 1, tr, l, r, x));
}

void calc(ll l, ll r)
{
    for (ll i = l; i <= r; i++)
        swap(a[i], b[i]);

    ll md = (l + r) >> 1;

    sf[md][0] = a[md];
    sf[md][1] = b[md];

    for (ll i = md - 1; i >= l; i--)
    {
        sf[i][0] = min(sf[i + 1][0], a[i]);
        sf[i][1] = min(sf[i + 1][1], b[i]);
    }

    pr[md + 1][0] = a[md + 1];
    pr[md + 1][1] = b[md + 1];

    for (ll i = md + 2; i <= r; i++)
    {
        pr[i][0] = min(pr[i - 1][0], a[i]);
        pr[i][1] = min(pr[i - 1][1], b[i]);
    }

    bld(1, md + 1, r);

    ll i1 = md;

    ll i2 = md + 1;

    for (ll i = md; i >= l; i--)
    {
        while (i1 < r && pr[i1 + 1][1] >= sf[i][1])
            i1++;

        while (i2 <= r && sf[i][0] < pr[i2][0])
            i2++;

        if (i2 <= i1)
            ans = max(ans, get(1, md + 1, r, i2, i1, i - 1) * sf[i][1]);
    }
}

void solve(ll l, ll r)
{
    if (l == r)
        {
            ans = max(ans, 1ll * a[l] * b[l]);

            return;
        }

    ll md = (l + r) >> 1;

    solve(l, md);

    solve(md + 1, r);

    sf[md][0] = a[md];
    sf[md][1] = b[md];

    for (ll i = md - 1; i >= l; i--)
    {
        sf[i][0] = min(sf[i + 1][0], a[i]);
        sf[i][1] = min(sf[i + 1][1], b[i]);
    }

    pr[md + 1][0] = a[md + 1];
    pr[md + 1][1] = b[md + 1];

    for (ll i = md + 2; i <= r; i++)
    {
        pr[i][0] = min(pr[i - 1][0], a[i]);
        pr[i][1] = min(pr[i - 1][1], b[i]);
    }

    ll j1 = md, j2 = md;

    for (ll i = md; i >= l; i--)
    {
        while (j1 < r && pr[j1 + 1][0] >= sf[i][0])
            j1++;

        while (j2 < r && pr[j2 + 1][1] >= sf[i][1])
            j2++;

        ll mx = min(j1, j2);

        if (mx > md)
            ans = max(ans, 1ll * (mx - i + 1) * sf[i][0] * sf[i][1]);
    }

    j1 = md + 1; j2 = md + 1;

    for (ll i = md + 1; i <= r; i++)
    {
        while (j1 > l && sf[j1 - 1][0] >= pr[i][0])
            j1--;

        while (j2 > l && sf[j2 - 1][1] >= pr[i][1])
            j2--;

        ll mx = max(j1, j2);

        if (mx < md + 1)
            ans = max(ans, 1ll * (i - mx + 1) * pr[i][0] * pr[i][1]);
    }

    calc(l, r);

    calc(l, r);
}

int main()
{
    ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);

//    freopen("1.in", "r", stdin);

    cin >> n;

    for (ll i = 1; i <= n; i++)
        cin >> a[i] >> b[i];

    solve(1, n);

    pri(ans);
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 23984 KB Output is correct
2 Correct 15 ms 23944 KB Output is correct
3 Correct 19 ms 23884 KB Output is correct
4 Correct 16 ms 23988 KB Output is correct
5 Correct 16 ms 23956 KB Output is correct
6 Correct 15 ms 23944 KB Output is correct
7 Correct 15 ms 23904 KB Output is correct
8 Correct 16 ms 23884 KB Output is correct
9 Correct 15 ms 23900 KB Output is correct
10 Correct 15 ms 24012 KB Output is correct
11 Correct 17 ms 23828 KB Output is correct
12 Correct 15 ms 23892 KB Output is correct

Subtask #2
90.0 / 90.0

# Verdict Execution time Memory Grader output
1 Correct 19 ms 23984 KB Output is correct
2 Correct 15 ms 23944 KB Output is correct
3 Correct 19 ms 23884 KB Output is correct
4 Correct 16 ms 23988 KB Output is correct
5 Correct 16 ms 23956 KB Output is correct
6 Correct 15 ms 23944 KB Output is correct
7 Correct 15 ms 23904 KB Output is correct
8 Correct 16 ms 23884 KB Output is correct
9 Correct 15 ms 23900 KB Output is correct
10 Correct 15 ms 24012 KB Output is correct
11 Correct 17 ms 23828 KB Output is correct
12 Correct 15 ms 23892 KB Output is correct
13 Correct 516 ms 39424 KB Output is correct
14 Correct 273 ms 39372 KB Output is correct
15 Correct 649 ms 39672 KB Output is correct
16 Correct 505 ms 39472 KB Output is correct
17 Correct 749 ms 41796 KB Output is correct
18 Correct 562 ms 41984 KB Output is correct
19 Correct 553 ms 41156 KB Output is correct
20 Correct 578 ms 41768 KB Output is correct
21 Correct 517 ms 39488 KB Output is correct
22 Correct 696 ms 41764 KB Output is correct
23 Correct 52 ms 25284 KB Output is correct
24 Correct 405 ms 39420 KB Output is correct