Submission #980433

#	Time	Username	Problem	Language	Result	Execution time	Memory
980433		vjudge1	Hexagonal Territory (APIO21_hexagon)	C++17	21 / 100	2100 ms	369392 KiB

hexagon

#include "hexagon.h"

#include <bits/stdc++.h>

using namespace std;

const int mod = 1e9 + 7;

long long pw(long long x, long long n) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) {
            res = res * x % mod;
        }
        n /= 2;
        x = x * x % mod;
    }
    return res;
}

int dx[6] = {-1, -1, 0, 1, 1, 0};
int dy[6] = {-1, 0, 1, 1, 0, -1};

int draw_territory(int N, int A, int B,
                   std::vector<int> D, std::vector<int> L) {

    long long X = 0, Y = 0;

    if (N == 3) {
        assert (L[0] == L[1]);
        assert (L[1] == L[2]);

        long long x = L[0] + 1;
        X = x * (x + 1) / 2;
        Y = x * (x + 1) % mod * (2 * x + 1) % mod * pw(6, mod - 2) - X;
    } else {
        vector<pair<int, int>> p;
        set<pair<int, int>> fucked;

        int x = 0, y = 0;
        for (int i = 0; i < N; i++) {
            int dir = D[i] - 1;
            for (int j = 0; j < L[i]; j++) {
                x += dx[dir];
                y += dy[dir];
                p.push_back({x, y});

                for (int h = 0; h < 6; h++) {
                    fucked.insert({x + dx[h], y + dy[h]});
                }
            }
        }
        for (auto xi: p) {
            fucked.erase(xi);
        }

        set<pair<int, int>> outers;
        queue<pair<int, int>> q;

        q.push(*fucked.begin());
        outers.insert(*fucked.begin());

        while (!q.empty()) {
            int x = q.front().first;
            int y = q.front().second;
            q.pop();
            for (int i = 0; i < 6; i++) {
                int nx = x + dx[i];
                int ny = y + dy[i];
                if (fucked.find({nx, ny}) == fucked.end()) {
                    continue;
                } else if (outers.find({nx, ny}) == outers.end()) {
                    outers.insert({nx, ny});
                    q.push({nx, ny});
                }
            }
        }

        for (auto xi: p) {
            int x = xi.first;
            int y = xi.second;
            if (outers.find({x, y - 1}) != outers.end()) {
                X -= y - 1;
            }
            if (outers.find({x, y + 1}) != outers.end()) {
                X += y;
            }
        }
    }

    X %= mod;
    Y %= mod;

    long long res = X * A % mod + Y * B % mod;

    res = (res % mod + mod) % mod;

    return res;
}

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 0 / 11
• Subtask 4: 12 / 12
• Subtask 5: 0 / 15
• Subtask 6: 0 / 19
• Subtask 7: 0 / 18
• Subtask 8: 0 / 16