Submission #1046372

#	Time	Username	Problem	Language	Result	Execution time	Memory
1046372		LucaIlie	Park (BOI16_park)	C++17	27 / 100	69 ms	10200 KiB

park

#include <bits/stdc++.h>

#define BOTTOM_SIDE n
#define RIGHT_SIDE n + 1
#define TOP_SIDE n + 2
#define LEFT_SIDE n + 3

#define BOTTOM_LEFT 0
#define BOTTOM_RIGHT 1
#define TOP_RIGHT 2
#define TOP_LEFT 3


using namespace std;

struct point {
    int x, y;
};

int dist( point a, point b ) {
    return sqrt( (long long)(a.x - b.x) * (a.x - b.x) + (long long)(a.y - b.y) * (a.y - b.y) );
}

struct circle {
    point c;
    int r;
};

struct event {
    int i, j;
};

struct query {
    int e, r;
    bool ans[4];
};

struct DSU {
    int n;
    vector<int> parent;

    void init( int _n ) {
        n = _n;
        parent.resize( n );
        for ( int i = 0; i < n; i++ )
            parent[i] = i;
    }

    int findRoot( int v ) {
        if ( parent[v] == v )
            return v;
        parent[v] = findRoot( parent[v] );
        return parent[v];
    }

    void connect( int u, int v ) {
        u = findRoot( u );
        v = findRoot( v );
        parent[u] = v;
    }

    bool areConnected( int u, int v ) {
        return findRoot( u ) == findRoot( v );
    }
};

const int MAX_N = 2e3;
const int MAX_Q = 1e5;
circle trees[MAX_N];
query queries[MAX_Q];
map<int, vector<event>> eventsByTime;
map<int, vector<int>> queriesByTime;
DSU dsu;

int main() {
    int n, q, w, h;

    cin >> n >> q >> w >> h;
    for ( int i = 0; i < n; i++ )
        cin >> trees[i].c.x >> trees[i].c.y >> trees[i].r;
    for ( int i = 0; i < q; i++ ) {
        cin >> queries[i].r >> queries[i].e;
        queries[i].e--;
        for ( int e = 0; e < 4; e++ )
            queries[i].ans[e] = (e == queries[i].e);
        queriesByTime[queries[i].r].push_back( i );
    }

    dsu.init( n + 4 );
    for ( int i = 0; i < n; i++ ) {
        for ( int j = i + 1; j < n; j++ ) {
            int d = (dist( trees[i].c, trees[j].c ) - trees[i].r - trees[j].r) / 2;
            if ( d < queries[0].r )
                dsu.connect( i, j );
            //else
              //  eventsByTime[d].push_back( { i, j } );
        }
    }
    for ( int i = 0; i < n; i++ ) {
        eventsByTime[(trees[i].c.x - trees[i].r) / 2].push_back( { i, LEFT_SIDE } );
        eventsByTime[(w - (trees[i].c.x + trees[i].r)) / 2].push_back( { i, RIGHT_SIDE } );
        eventsByTime[(trees[i].c.y - trees[i].r) / 2].push_back( { i, BOTTOM_SIDE } );
        eventsByTime[(h - (trees[i].c.y + trees[i].r)) / 2].push_back( { i, TOP_SIDE } );
    }

    vector<int> relevantTimes;
    for ( auto p: eventsByTime )
        relevantTimes.push_back( p.first );
    for ( auto p: queriesByTime )
        relevantTimes.push_back( p.first );
    sort( relevantTimes.begin(), relevantTimes.end() );
    relevantTimes.resize( unique( relevantTimes.begin(), relevantTimes.end() ) - relevantTimes.begin() );

    for ( int t: relevantTimes ) {
        for ( int ind: queriesByTime[t] ) {
            int e = queries[ind].e;

            bool isClockwisePossible = true;
            for ( int i = 0; i < 4; i++ ) {
                int s1 = n + e, s2 = n + i;
                if ( s1 != s2 )
                    isClockwisePossible &= (!dsu.areConnected( s1, s2 ));
            }
            queries[ind].ans[(e + 1) % 4] = isClockwisePossible;

            bool isDiagPossible = true;
            for ( int i = 0; i < 2; i++ ) {
                for ( int j = 2; j < 4; j++ ) {
                    int s1 = n + (e + i) % 4, s2 = n + (e + j) % 4;
                    if ( s1 != s2 )
                        isDiagPossible &= (!dsu.areConnected( s1, s2 ));
                }
            }
            queries[ind].ans[(e + 2) % 4] = isDiagPossible;

            bool isCounterclockwisePossible = true;
            for ( int i = 0; i < 4; i++ ) {
               int s1 = n + (e + 3) % 4, s2 = n + i;
               if ( s1 != s2 )
                   isCounterclockwisePossible &= (!dsu.areConnected( s1, s2 ));
            }
            queries[ind].ans[(e + 3) % 4] = isCounterclockwisePossible;
        }

        for ( event e: eventsByTime[t] )
            dsu.connect( e.i, e.j );
    }

    for ( int i = 0; i < q; i++ ) {
        for ( int e = 0; e < 4; e++ ) {
            if ( queries[i].ans[e] )
                cout << (e + 1);
        }
        cout << "\n";
    }

    return 0;
}

• Subtask 1: 27 / 27
• Subtask 2: 0 / 31
• Subtask 3: 0 / 42