Submission #47090

#	Time	Username	Problem	Language	Result	Execution time	Memory
47090		SpaimaCarpatilor	Cultivation (JOI17_cultivation)	C++17	80 / 100	1843 ms	6120 KiB

cultivation

#include<bits/stdc++.h>

using namespace std;

int N, R, C, x[309], y[309], precalc[309][309][3];
const int INF = 1e9 + 100;
long long ans = 1LL << 60;
set < int > sa, sb, sab;

namespace ds {
    multiset < int > xs, dx;

    void init ()
    {
        xs.clear (), dx.clear ();
    }

    void delDif (int x)
    {
        dx.erase (dx.find (x));
    }

    void add (int x)
    {
        if (xs.find (x) != xs.end ()) xs.insert (x);
        else
        {
            xs.insert (x);
            auto it1 = xs.lower_bound (x), it2 = xs.upper_bound (x);
            if (it1 != xs.begin () && it2 != xs.end ())
                it1 --,
                delDif ((*it2) - (*it1)),
                it1 ++;
            if (it1 != xs.begin ())
                it1 --,
                dx.insert (x - (*it1));
            if (it2 != xs.end ())
                dx.insert ((*it2) - x);
        }
    }

    void del (int x)
    {
        if (xs.count (x) >= 2) xs.erase (xs.find (x));
        else
        {
            auto it1 = xs.lower_bound (x), it2 = xs.upper_bound (x);
            if (it1 != xs.begin () && it2 != xs.end ())
                it1 --,
                dx.insert ((*it2) - (*it1)),
                it1 ++;
            if (it1 != xs.begin ())
                it1 --,
                delDif (x - (*it1));
            if (it2 != xs.end ())
                delDif ((*it2) - x);
            xs.erase (x);
        }
    }

    int maxDif ()
    {
        if (dx.empty ()) return 0;
        return *(dx.rbegin ());
    }

    int getA ()
    {
        if (xs.empty ()) return INF;
        return (*xs.begin ()) - 1;
    }

    int getB ()
    {
        if (xs.empty ()) return INF;
        return C - (*xs.rbegin ());
    }

    void store (int &a, int &b, int &df)
    {
        a = getA ();
        b = getB ();
        df = maxDif () - 1;
    }
};

long long pos[1209];
int nr, stat[1209][3];
vector < pair < long long, int > > events;
deque < int > dq[3];

void clearDeque ()
{
    for (int i=0; i<3; i++)
        while (!dq[i].empty ())
            dq[i].pop_back ();
}

void add (int pos)
{
    for (int i=0; i<3; i++)
    {
        while (!dq[i].empty () && stat[dq[i].back ()][i] <= stat[pos][i])
            dq[i].pop_back ();
        dq[i].push_back (pos);
    }
}

void del (int pos)
{
    for (int i=0; i<3; i++)
        while (!dq[i].empty () && dq[i].front () <= pos)
            dq[i].pop_front ();
}

int getSum ()
{
    if (dq[0].empty ()) return 2 * INF;
    int minA = stat[dq[0].front ()][0], minB = stat[dq[1].front ()][1], minAB = stat[dq[2].front ()][2];
    return max (minA + minB, minAB);
}

void solve (int updown)
{
    ds::init ();
    clearDeque ();
    vector < long long > relevantXs, relevantX1, relevantX2;
    for (int i=1; i<=N; i++)
        relevantX1.push_back (x[i]),
        relevantX2.push_back (x[i] + updown + 1);
    relevantXs.resize (relevantX1.size () + relevantX2.size ());
    merge (relevantX1.begin (), relevantX1.end (), relevantX2.begin (), relevantX2.end (), relevantXs.begin ());

    nr = 1, pos[1] = -(1LL << 60), stat[1][0] = INF, stat[1][1] = INF, stat[1][2] = -1;
    int l = 1, r = 0;
    for (auto t : relevantXs)
    {
        while (r < N && x[r + 1] <= t)
            r ++;
        while (x[l] + updown < t && l <= N)
            l ++;
        nr ++, pos[nr] = t;
        stat[nr][0] = precalc[l][r][0];
        stat[nr][1] = precalc[l][r][1];
        stat[nr][2] = precalc[l][r][2];
    }
    pos[nr + 1] = 1LL << 60;
/*    printf ("%d ->\n", updown);
    for (int i=1; i<=nr; i++)
        printf ("%7lld %7d %7d %7d\n", pos[i], stat[i][0], stat[i][1], stat[i][2]);*/
    vector < long long > relevantShifts, relevantS1, relevantS2;
    for (int i=1; i<=nr; i++)
    {
        if (pos[i] - 1 <= updown) relevantS1.push_back (pos[i] - 1);
        if (pos[i] - R >= 0 && pos[i] - R <= updown) relevantS2.push_back (pos[i] - R);
    }
    relevantShifts.resize (relevantS1.size () + relevantS2.size ());
    merge (relevantS1.begin (), relevantS1.end (), relevantS2.begin (), relevantS2.end (), relevantShifts.begin ());
    relevantShifts.push_back (updown);
    int j = 1, i = 1;
    for (auto shift : relevantShifts)
    {
        while (j <= nr && pos[j] <= R + shift)
            add (j), j++;
        while (pos[i + 1] - 1 < 1 + shift)
            del (i), i ++;
        long long curr = (long long) updown + getSum ();
        if (curr < ans)
            ans = curr;
    }
}

void readAndSort ()
{
    pair < int, int > point[309];
    scanf ("%d %d\n", &R, &C);
    scanf ("%d", &N);
    for (int i=1; i<=N; i++)
        scanf ("%d %d", &point[i].first, &point[i].second);
    sort (point + 1, point + N + 1);
    for (int i=1; i<=N; i++)
        x[i] = point[i].first, y[i] = point[i].second;
}

void doPrecalc ()
{
    for (int i=1; i<=N + 1; i++)
    {
        ds::init ();
        ds::store (precalc[i][i - 1][0], precalc[i][i - 1][1], precalc[i][i - 1][2]);
        for (int j=i; j<=N; j++)
            ds::add (y[j]),
            ds::store (precalc[i][j][0], precalc[i][j][1], precalc[i][j][2]);
    }
}

int main ()
{
//freopen ("input", "r", stdin);
//freopen ("output", "w", stdout);

readAndSort ();
doPrecalc ();
for (int i=1; i<=N; i++)
    sa.insert (x[i] - 1), sb.insert (R - x[i]);
for (int i=1; i<=N; i++)
    for (int j=i + 1; j<=N; j++)
    if (x[i] != x[j])
    {
        int val = x[i] - x[j];
        if (val < 0) val = -val;
        sab.insert (val - 1);
    }
for (auto a : sa)
    for (auto b : sb)
        sab.insert (a + b);
int steps = 0;
for (auto ab : sab)
{
    if (ans >= ab)
        solve (ab), steps ++;
    if (steps == 70000)
        break;
}
printf ("%lld\n", ans);
return 0;
}

Compilation message (stderr)

cultivation.cpp: In function 'void readAndSort()':
cultivation.cpp:176:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d %d\n", &R, &C);
     ~~~~~~^~~~~~~~~~~~~~~~~~~
cultivation.cpp:177:11: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf ("%d", &N);
     ~~~~~~^~~~~~~~~~
cultivation.cpp:179:15: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf ("%d %d", &point[i].first, &point[i].second);
         ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 30 / 30
• Subtask 5: 20 / 20
• Subtask 6: 0 / 20