Submission #569662

#	Time	Username	Problem	Language	Result	Execution time	Memory
569662		hoanghq2004	Hexagonal Territory (APIO21_hexagon)	C++14	41 / 100	737 ms	191140 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;
}

const int M = 4010;
int vis[M][M];
int ok[M][M], d[M][M];

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 {
        int x = 2005, y = 2005;
        int delta = 0;
        for (int i = 0; i < D.size(); ++i) {
            --D[i];
            delta += L[i];
            for (int j = 0; j < L[i]; ++j) {
                x += dx[D[i]];
                y += dy[D[i]];
                vis[x][y] = 1;
            }
        }
        auto bfs = [&](int x, int y) {
            int reach = 0;
            queue <pair <int, int>> q;
            q.push({x, y});
            ok[x][y] = 1;
            vector <pair <int, int>> s;
            while (q.size()) {
                auto [x, y] = q.front();
                s.push_back({x, y});
                ok[x][y] = 1;
                q.pop();
                for (int i = 0; i < 6; ++i) {
                    int u = x + dx[i];
                    int v = y + dy[i];
                    if (u < 0 || u >= M || v < 0 || v >= M) {
                        reach = 1;
                        continue;
                    }
                    if (vis[u][v] || ok[u][v]) continue;
                    ok[u][v] = 1;
                    q.push({u, v});
                }
            }
            if (reach) return;
            for (auto [x, y]: s) vis[x][y] = 1;
        };
        for (int i = 0; i < M; ++i)
            for (int j = 0; j < M; ++j)
                if (vis[i][j] == 0 && ok[i][j] == 0) bfs(i, j);
        queue <pair <int, int>> q;
        q.push({x, y});
        memset(d, -1, sizeof(d));
        d[x][y] = 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[u][v] == 0 || d[u][v] != -1) continue;
                d[u][v] = d[x][y] + 1;
                q.push({u, v});
            }
        }
        int ans = 0;
        for (int i = 0; i < M; ++i)
            for (int j = 0; j < M; ++j)
                if (d[i][j] != -1) ans = (ans + 1LL * B * d[i][j] + A) % mod;
        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:54:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Vector>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |         for (int i = 1; i < P.size(); ++i) S += P[i - 1] * P[i];
      |                         ~~^~~~~~~~~~
hexagon.cpp:62:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |         for (int i = 0; i < D.size(); ++i) {
      |                         ~~^~~~~~~~~~
hexagon.cpp: In lambda function:
hexagon.cpp:78:22: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   78 |                 auto [x, y] = q.front();
      |                      ^
hexagon.cpp:95:23: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   95 |             for (auto [x, y]: s) vis[x][y] = 1;
      |                       ^
hexagon.cpp: In function 'int draw_territory(int, int, int, std::vector<int>, std::vector<int>)':
hexagon.cpp:105:18: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  105 |             auto [x, y] = q.front();
      |                  ^

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