Submission #1196702

#	Time	Username	Problem	Language	Result	Execution time	Memory
1196702		mmaiti	Toy (CEOI24_toy)	C++20	73 / 100	1594 ms	15028 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define vi vector<int>
#define si set<int>
#define usi unordered_set<int>
#define sll set<ll>
#define usll unordered_set<ll>
#define vb vector<bool>
#define vll vector<ll>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define vvi vector<vector<int>>
#define vvll vector<vector<ll>>

// xh, yh, xv, yv
bool visited[1500][1500];
void solve() {
  int W, H, K, L;
  cin >> W >> H >> K >> L;
  int xh, yh, xv, yv, gx, gy;
  cin >> yh >> xh >> yv >> xv;
  vector<string> grid(H);
  for (int i = 0; i < H; i++)
    cin >> grid[i];

  vector<vi> psum(H + 1, vi(W + 1));
  for (int i = 0; i < H; i++) {
    for (int j = 0; j < W; j++) {
      if (grid[i][j] == '*') {
        gx = i;
        gy = j;
      }
      psum[i + 1][j + 1] =
          (grid[i][j] == 'X') + psum[i][j + 1] + psum[i + 1][j] - psum[i][j];
    }
  }

  vll dx{-1, 0, 1, 0};
  vll dy{0, 1, 0, -1};
  queue<pair<int, int>> q;
  q.push(make_pair(xh, yv));

  // x1, y1 are top left, x2, y2 are bottom right
  // all values are 0 indexed
  auto queryRegion = [&](ll x1, ll y1, ll x2, ll y2) {
    return psum[x2 + 1][y2 + 1] - psum[x1][y2 + 1] - psum[x2 + 1][y1] +
           psum[x1][y1];
  };
  auto checkCoord = [&](ll x, ll y) {
    return (x >= 0 && x < H && y >= 0 && y < W);
  };
  // x1, y1 are horizontal piece; x2, y2 are vertical piece
  auto checkHoriz = [&](ll x1, ll y1) {
    bool works = true;
    works &= checkCoord(x1, y1);
    works &= checkCoord(x1, y1 + K - 1);
    if (!works)
      return false;

    // check no obstacle intersection
    works &= (queryRegion(x1, y1, x1, y1 + K - 1) == 0);
    return works;
  };
  auto checkVert = [&](ll x2, ll y2) {
    bool works = true;
    works &= checkCoord(x2, y2);
    works &= checkCoord(x2 + L - 1, y2);
    if (!works)
      return false;

    // check no obstacle intersection
    works &= (queryRegion(x2, y2, x2 + L - 1, y2) == 0);
    return works;
  };
  while (!q.empty()) {
    int cx, cy;
    tie(cx, cy) = q.front();
    q.pop();
    if (cx == gx && cy == gy) {
      cout << "YES\n";
      return;
    }
    for (int i = 0; i < 4; i++) {
      int nxh = cx + dx[i];
      int nyh = cy + dy[i];
      if (!checkCoord(nxh, nyh) || grid[nxh][nyh] == 'X' || visited[nxh][nyh])
        continue;
      if (abs(dy[i]) == 1) {
        for (int j = cx - L + 1; j <= cx; j++) {
          if (checkVert(j, cy) && checkVert(j, nyh)) {
            visited[nxh][nyh] = true;
            q.push({nxh, nyh});
          }
        }
      } else {
        for (int j = cy - K + 1; j <= cy; j++) {
          if (checkHoriz(cx, j) && checkHoriz(nxh, j)) {
            visited[nxh][nyh] = true;
            q.push({nxh, nyh});
          }
        }
      }
    }
  }

  cout << "NO\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  solve();
}

• Subtask 0: 0 / 0
• Subtask 1: 14 / 14
• Subtask 2: 21 / 21
• Subtask 3: 9 / 9
• Subtask 4: 29 / 29
• Subtask 5: 0 / 27