Submission #218645

#	Time	Username	Problem	Language	Result	Execution time	Memory
218645		Vimmer	Matching (COCI20_matching)	C++14	58 / 110	2563 ms	69112 KiB

matching

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

#define F first
#define S second
#define sz(x) int(x.size())
#define pb push_back
#define N 100005
#define M ll(998244353)

using namespace std;
//using namespace __gnu_pbds;

typedef long double ld;
typedef long long ll;
typedef short int si;

//typedef tree<int, null_type, less <int>, rb_tree_tag, tree_order_statistics_node_update> oredered_set;

int x[N], y[N], a[N][2], n, xr[N], yr[N];


set <int> tx[N * 4], ty[N * 4];

vector <int> pshx[N * 4], pshy[N * 4];

bool mk[N];

queue <pair <int, int> > qr;

queue <int> alone;

vector <pair <int, int> > vert, gorz;

void Push(int v, int tl, int tr)
{
    while (sz(pshx[v]) > 0)
    {
        int val = pshx[v].back();

        pshx[v].pop_back();

        tx[v].insert(val);

        if (tl != tr) {pshx[v + v].pb(val); pshx[v + v + 1].pb(val);}
    }

    while (sz(pshy[v]) > 0)
    {
        int val = pshy[v].back();

        pshy[v].pop_back();

        ty[v].insert(val);

        if (tl != tr) {pshy[v + v].pb(val); pshy[v + v + 1].pb(val);}
    }
}
void upd(int v, int tl, int tr, int l, int r, int val, bool f)
{
    Push(v, tl, tr);

    if (tl > tr || l > r || r < tl || tr < l) return;

    if (l <= tl && tr <= r) {if (!f) pshx[v].pb(val); else pshy[v].pb(val); Push(v, tl, tr); return;}

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

    upd(v + v, tl, md, l, r, val, f);

    upd(v + v + 1, md + 1, tr, l, r, val, f);
}

bool good(int v, int tl, int tr, int pos, int l, int r, bool f)
{
    Push(v, tl, tr);

    if (tl == tr)
    {
        set <int> :: iterator it;

        if (f)
        {
            it = ty[v].lower_bound(l);

            return (it == ty[v].end() ? 1 : *it > r);
        }
        else
        {
            it = tx[v].lower_bound(l);

            return (it == tx[v].end() ? 1 : *it > r);
        }
    }
    else
    {
        int md = (tl + tr) >> 1;

        if (pos <= md) return good(v + v, tl, md, pos, l, r, f);

        return good(v + v + 1, md + 1, tr, pos, l, r, f);
    }
}
bool gd(int fr, int sc)
{
    if (x[fr] == x[sc])
    {
        if (y[fr] > y[sc]) swap(fr, sc);

        return good(1, 1, N - 1, x[fr], y[fr], y[sc], 0);
    }
    else
    {
        if (x[fr] > x[sc]) swap(fr, sc);

        return good(1, 1, N - 1, y[fr], x[fr], x[sc], 1);
    }
}

void add(int fr, int sc)
{
    if (x[fr] == x[sc])
    {
        gorz.pb({fr, sc});

        if (y[fr] > y[sc]) swap(fr, sc);

        upd(1, 1, N - 1, y[fr], y[sc], x[fr], 1);
    }
    else
    {
        vert.pb({fr, sc});

        if (x[fr] > x[sc]) swap(fr, sc);

        upd(1, 1, N - 1, x[fr], x[sc], y[fr], 0);
    }
}

void clr(int x)
{
    mk[x] = 1;

    if (a[x][1] != -1) {if (!mk[a[x][1]]) alone.push(a[x][1]); a[x][1] = a[a[x][1]][1] = -1;}

    if (a[x][0] != -1) {if (!mk[a[x][0]]) alone.push(a[x][0]); a[x][0] = a[a[x][0]][0] = -1;}
}


void fnd()
{
    while (sz(alone) > 0)
    {
        int v = alone.front();

        alone.pop();

        if (mk[v]) continue;

        if (a[v][1] != -1 && gd(v, a[v][1])) {qr.push({a[v][1], v}); a[v][1] = a[a[v][1]][1] = -1; return;}

        if (a[v][0] != -1 && gd(v, a[v][0])) {qr.push({a[v][0], v}); a[v][0] = a[a[v][0]][0] = -1; return;}

        cout << "NE" << endl;

        exit(0);
    }

    for (int i = 0; i < n; i++)
    {
        if (mk[i]) continue;

        if (a[i][1] == -1 && a[i][0] == -1) {cout << "NE" << endl; exit(0);}

        bool f0 = gd(i, a[i][0]);

        bool f1 = gd(i, a[i][1]);

        if (f0 && f1) continue;

        if (!f0 && !f1) {cout << "NE" << endl; exit(0);}

        if (f0)
        {
            qr.push({i, a[i][0]});

            a[i][0] = a[a[i][0]][0] = -1;

            return;
        }
        else
        {
            qr.push({i, a[i][1]});

            a[i][1] = a[a[i][1]][1] = -1;

            return;
        }
    }

    for (int i = 0; i < n; i++)
    {
        if (mk[i]) continue;

        if (!gd(i, a[i][0]))
        {
            qr.push({i, a[i][1]});

            a[i][1] = a[a[i][1]][1] = -1;

            return;
        }
        else
        {
            qr.push({i, a[i][0]});

            a[i][0] = a[a[i][0]][0] = -1;

            return;
        }
    }
}

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

    cin >> n;

    for (int i = 1; i < N; i++) xr[i] = yr[i] = -1;

    for (int i = 0; i < n; i++) {cin >> x[i] >> y[i]; a[i][0] = a[i][1] = -1;}

    for (int i = 0; i < n; i++)
        {
            int X = x[i], Y = y[i];

            if (xr[X] == -1) xr[X] = i; else {a[i][0] = xr[X]; a[xr[X]][0] = i;}

            if (yr[Y] == -1) yr[Y] = i; else {a[i][1] = yr[Y]; a[yr[Y]][1] = i;}
        }

    for (int i = 0; i < n; i++) if (a[i][0] == a[i][1] && a[i][1] == -1) {cout << "NE" << endl; exit(0);}

    for (int i = 0; i < n; i++) if (a[i][0] == -1 || a[i][1] == -1) alone.push(i);

    fnd();

    while (sz(qr) > 0)
    {
        int fr = qr.front().F;

        int sc = qr.front().S;

        qr.pop();

        if (gd(fr, sc))
        {
            clr(fr);

            clr(sc);

            add(fr, sc);
        }

        fnd();
    }

    if (sz(vert) + sz(gorz) != n / 2) {cout << "NE" << endl; exit(0);}

    cout << "DA" << endl;

    for (auto it : gorz) cout << it.F + 1 << " " << it.S + 1 << endl;

    for (auto it : vert) cout << it.F + 1 << " " << it.S + 1 << endl;
}

• Subtask 1: 5 / 5
• Subtask 2: 6 / 6
• Subtask 3: 7 / 7
• Subtask 4: 40 / 40
• Subtask 5: 0 / 52