Submission #218464

#	Time	Username	Problem	Language	Result	Execution time	Memory
218464		Vimmer	Matching (COCI20_matching)	C++14	11 / 110	5 ms	640 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;

bool mk[N];

queue <pair <int, int> > qr;

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

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

        if (a[i][1] == -1 && a[i][0] == -1) continue;

        if (a[i][1] != -1 && a[i][0] != -1) continue;

        if (a[i][1] != -1) {qr.push({a[i][1], a[a[i][1]][1]}); mk[i] = 1; mk[a[i][1]] = 1; a[i][1] = a[a[i][1]][1] = -1; return;}

        if (a[i][0] != -1) {qr.push({a[i][0], a[a[i][0]][0]}); mk[i] = 1; mk[a[i][0]] = 1; a[i][0] = a[a[i][0]][0] = -1; return;}
    }

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

        if (a[i][1] == -1 && a[i][0] == -1) continue;

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

        mk[i] = mk[a[i][1]] = 1;

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

        return;
    }
}

bool gd(int fr, int sc)
{
    if (x[fr] == x[sc])
    {
        if (y[fr] > y[sc]) swap(fr, sc);

        for (auto it : vert)
        {
            int _fr = it.F, _sc = it.S;

            if (x[_fr] > x[_sc]) swap(_fr, _sc);

            if (y[_fr] < y[fr] || y[sc] < y[_fr]) continue;

            if (x[fr] < x[_fr] || x[_sc] < x[fr]) continue;

            return 0;
        }
    }
    else
    {
        if (x[fr] > x[sc]) swap(fr, sc);

        for (auto it : gorz)
        {
            int _fr = it.F, _sc = it.S;

            if (y[_fr] > y[_sc]) swap(_fr, _sc);

            if (x[_fr] < x[fr] || x[sc] < x[_fr]) continue;

            if (y[fr] < y[_fr] || y[_sc] < y[fr]) continue;

            return 0;
        }
    }

    return 1;
}
void clr(int x)
{
    if (a[x][1] != -1) a[x][1] = a[a[x][1]][1] = -1;

    if (a[x][0] != -1) a[x][0] = a[a[x][0]][0] = -1;
}
int main()
{
    ios_base::sync_with_stdio(0); istream::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    cin >> n;

    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++)
        for (int j = i + 1; j < n; j++)
          if (x[i] == x[j]) {a[i][0] = j; a[j][0] = i;}
            else if (y[i] == y[j]) {a[i][1] = j; a[j][1] = 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);

            if (x[fr] == x[sc]) gorz.pb({fr, sc}); else vert.pb({fr, sc});
        }
        else mk[fr] = mk[sc] = 0;

        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: 0 / 7
• Subtask 4: 0 / 40
• Subtask 5: 0 / 52