Submission #569645

#	Time	Username	Problem	Language	Result	Execution time	Memory
569645		hoanghq2004	Hexagonal Territory (APIO21_hexagon)	C++14	30 / 100	2070 ms	357548 KiB

hexagon

#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include "hexagon.h"

using namespace __gnu_pbds;
using namespace std;

template <typename T>
using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;

const int mod = 1e9 + 7;
const int N = 2e5 + 10;

struct Vector {
    long long x, y;
    Vector operator - (const Vector& other) const {
        return {x - other.x, y - other.y};
    }
    long long operator * (const Vector& other) const {
        return x * other.y - y * other.x;
    }
} P[N];

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

int power(int a, int n) {
    int ans = 1;
    for (; n; n >>= 1, a = 1LL * a * a % mod)
        if (n & 1) ans = 1LL * ans * a % mod;
    return ans;
}

int draw_territory(int N, int A, int B, vector<int> D, vector<int> L) {
    if (B == 0) {
        vector <Vector> P = {{0, 0}};
        long long x = 0, y = 0, b = 0;
        for (int i = 0; i < N; ++i) {
            --D[i];
            x += L[i] * dx[D[i]];
            y += L[i] * dy[D[i]];
            b = (b + L[i]) % mod;
            P.push_back({x, y});
        }
        long long S = 0;
        for (int i = 1; i < P.size(); ++i) S += P[i - 1] * P[i];
        S = abs(S);
        S %= mod;
        long long i = ((1LL * (S - b + 2 + mod) * power(2, mod - 2)) + b) % mod;
        return i * A % mod;
    } else {
        set <pair <int, int>> vis, ok;
        int x = 0, y = 0;
        for (int i = 0; i < D.size(); ++i) {
            --D[i];
            for (int j = 0; j < L[i]; ++j) {
                x += dx[D[i]];
                y += dy[D[i]];
                vis.insert({x, y});
            }
        }
//        cout << N << "sadfdsgf\n";
        auto bfs = [&](int x, int y) {
            int reach = 0;
            queue <pair <int, int>> q;
            q.push({x, y});
            ok.insert({x, y});
            vector <pair <int, int>> s;
            while (q.size()) {
                auto [x, y] = q.front();
                s.push_back({x, y});
                ok.insert({x, y});
                q.pop();
                for (int i = 0; i < 6; ++i) {
                    int u = x + dx[i];
                    int v = y + dy[i];
                    if (vis.find({u, v}) != vis.end()) continue;
                    if (ok.find({u, v}) != ok.end()) continue;
                    if (u < - N || u > N || v < - N || v > N) {
                        reach = 1;
                        continue;
                    }
                    ok.insert({u, v});
                    q.push({u, v});
                }
            }
            if (reach) return;
//            cout << s.size() << "sdgdsgffg\n";
//            cout << s[0].first << ' ' << s[0].second << "vv\n";
            for (auto [x, y]: s) vis.insert({x, y});
        };
        for (int i = - N; i <= N; ++i)
            for (int j = - N; j <= N; ++j)
                if (ok.find({i, j}) == ok.end()) bfs(i, j);

        queue <pair <int, int>> q;
        q.push({0, 0});
        map <pair <int, int>, int> d;
        d[{0, 0}] = 0;
        while (q.size()) {
            auto [x, y] = q.front();
            q.pop();
            for (int i = 0; i < 6; ++i) {
                int u = x + dx[i];
                int v = y + dy[i];
                if (vis.find({u, v}) == vis.end() || d.find({u, v}) != d.end()) continue;
                d[{u, v}] = d[{x, y}] + 1;
                q.push({u, v});
            }
        }
//        cout << vis.size() << '\n';
        int ans = 0;
        for (auto [_, val]: d) ans = (ans + 1LL * B * val + A) % mod;
//        cout << d.size() << '\n';
        return ans;
    }
}

//int main() {
//  int N, A, B;
//  assert(3 == scanf("%d %d %d", &N, &A, &B));
//  std::vector<int> D(N), L(N);
//  for (int i = 0; i < N; ++i) {
//    assert(2 == scanf("%d %d", &D[i], &L[i]));
//  }
//
//  int result = draw_territory(N, A, B, D, L);
//  printf("%d\n", result);
//  return 0;
//}

Compilation message (stderr)

hexagon.cpp: In function 'int draw_territory(int, int, int, std::vector<int>, std::vector<int>)':
hexagon.cpp:49:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Vector>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |         for (int i = 1; i < P.size(); ++i) S += P[i - 1] * P[i];
      |                         ~~^~~~~~~~~~
hexagon.cpp:57:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |         for (int i = 0; i < D.size(); ++i) {
      |                         ~~^~~~~~~~~~
hexagon.cpp: In lambda function:
hexagon.cpp:73:22: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   73 |                 auto [x, y] = q.front();
      |                      ^
hexagon.cpp:93:23: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   93 |             for (auto [x, y]: s) vis.insert({x, y});
      |                       ^
hexagon.cpp: In function 'int draw_territory(int, int, int, std::vector<int>, std::vector<int>)':
hexagon.cpp:104:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  104 |             auto [x, y] = q.front();
      |                  ^
hexagon.cpp:116:19: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  116 |         for (auto [_, val]: d) ans = (ans + 1LL * B * val + A) % mod;
      |                   ^

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