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Submission #495711

# Submission time Handle Problem Language Result Execution time Memory
495711 2021-12-20T03:25:58 Z chenwz Mecho (IOI09_mecho) C++11
100 / 100
 180 ms 21600 KB 
#include <bits/stdc++.h>
using namespace std;
const int NN = 2000 + 4, DX[4] = {1, -1, 0, 0}, DY[4] = {0, 0, 1, -1};
#define _for(i, a, b) for (int i = (a); i < (int)(b); ++i)
string G[NN];
int N, S, D[NN][NN];
bool Vis[NN][NN];
struct Point {
  int x, y;
};
bool check(const Point& st, int delay) {
  if (delay * S >= D[st.x][st.y]) return false;
  queue<pair<int, Point> > Q;
  memset(Vis, 0, sizeof(Vis)), Q.push({delay * S, st}), Vis[st.x][st.y] = true;
  while (!Q.empty()) {
    auto p = Q.front();
    Q.pop();
    int d = p.first, x = p.second.x, y = p.second.y;
    if (G[x][y] == 'D') return true;
    _for(i, 0, 4) {
      int nx = x + DX[i], ny = y + DY[i];
      if (nx < 0 || nx >= N || ny < 0 || ny >= N || G[nx][ny] == 'T' ||
          (d + 1) >= D[nx][ny] || Vis[nx][ny])
        continue;
      Q.push({d + 1, {nx, ny}}), Vis[nx][ny] = true;
    }
  }
  return false;
}
int main() {
  ios::sync_with_stdio(false), cin.tie(0);
  cin >> N >> S;
  queue<Point> Q;
  Point Honey, Home;
  memset(D, -1, sizeof(D));
  _for(i, 0, N) {
    cin >> G[i];
    _for(j, 0, N) {
      char& c = G[i][j];
      if (c == 'H') Q.push({i, j}), D[i][j] = 0;
      if (c == 'M') Honey = {i, j}, c = 'G';
      if (c == 'D') Home = {i, j};
    }
  }
  while (!Q.empty()) {
    Point p = Q.front();
    Q.pop();
    _for(i, 0, 4) {
      int nx = p.x + DX[i], ny = p.y + DY[i];
      if (nx < 0 || nx >= N || ny < 0 || ny >= N || G[nx][ny] != 'G' ||
          D[nx][ny] != -1)
        continue;
      D[nx][ny] = D[p.x][p.y] + S, Q.push({nx, ny});
    }
  }
  D[Home.x][Home.y] = N * N * S;
  int L = -1, R = 2 * N * N;
  while (L + 1 < R) {
    int mid = (L + R) / 2;
    (check(Honey, mid) ? L : R) = mid;
  }
  cout << L << endl;
  return 0;
}

Compilation message

mecho.cpp: In function 'int main()':
mecho.cpp:56:21: warning: 'Home.Point::x' may be used uninitialized in this function [-Wmaybe-uninitialized]
   56 |   D[Home.x][Home.y] = N * N * S;
      |   ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
mecho.cpp:56:21: warning: 'Home.Point::y' may be used uninitialized in this function [-Wmaybe-uninitialized]

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 19916 KB Output is correct
2 Correct 9 ms 19916 KB Output is correct
3 Correct 9 ms 19948 KB Output is correct
4 Correct 9 ms 19968 KB Output is correct
5 Correct 10 ms 19908 KB Output is correct
6 Correct 8 ms 19916 KB Output is correct
7 Correct 82 ms 21316 KB Output is correct
8 Correct 8 ms 19916 KB Output is correct
9 Correct 11 ms 19964 KB Output is correct
10 Correct 13 ms 19960 KB Output is correct
11 Correct 9 ms 19916 KB Output is correct
12 Correct 9 ms 20044 KB Output is correct
13 Correct 9 ms 19916 KB Output is correct
14 Correct 9 ms 19960 KB Output is correct
15 Correct 10 ms 19916 KB Output is correct
16 Correct 9 ms 19916 KB Output is correct
17 Correct 11 ms 19992 KB Output is correct
18 Correct 9 ms 19924 KB Output is correct
19 Correct 8 ms 19968 KB Output is correct
20 Correct 9 ms 19972 KB Output is correct
21 Correct 9 ms 19916 KB Output is correct
22 Correct 10 ms 20044 KB Output is correct
23 Correct 9 ms 20004 KB Output is correct
24 Correct 8 ms 19916 KB Output is correct
25 Correct 10 ms 19988 KB Output is correct
26 Correct 9 ms 19996 KB Output is correct
27 Correct 9 ms 20044 KB Output is correct
28 Correct 11 ms 19916 KB Output is correct
29 Correct 10 ms 19916 KB Output is correct
30 Correct 10 ms 20044 KB Output is correct
31 Correct 11 ms 20016 KB Output is correct
32 Correct 11 ms 19924 KB Output is correct
33 Correct 12 ms 20172 KB Output is correct
34 Correct 14 ms 20224 KB Output is correct
35 Correct 27 ms 20256 KB Output is correct
36 Correct 12 ms 20292 KB Output is correct
37 Correct 12 ms 20296 KB Output is correct
38 Correct 35 ms 20348 KB Output is correct
39 Correct 16 ms 20312 KB Output is correct
40 Correct 14 ms 20344 KB Output is correct
41 Correct 47 ms 20424 KB Output is correct
42 Correct 14 ms 20428 KB Output is correct
43 Correct 16 ms 20412 KB Output is correct
44 Correct 50 ms 20520 KB Output is correct
45 Correct 15 ms 20592 KB Output is correct
46 Correct 17 ms 20556 KB Output is correct
47 Correct 56 ms 20596 KB Output is correct
48 Correct 15 ms 20736 KB Output is correct
49 Correct 15 ms 20668 KB Output is correct
50 Correct 96 ms 20756 KB Output is correct
51 Correct 19 ms 20796 KB Output is correct
52 Correct 17 ms 20760 KB Output is correct
53 Correct 76 ms 20876 KB Output is correct
54 Correct 20 ms 20932 KB Output is correct
55 Correct 16 ms 20936 KB Output is correct
56 Correct 101 ms 21012 KB Output is correct
57 Correct 20 ms 21060 KB Output is correct
58 Correct 18 ms 21124 KB Output is correct
59 Correct 103 ms 21160 KB Output is correct
60 Correct 19 ms 21244 KB Output is correct
61 Correct 18 ms 21228 KB Output is correct
62 Correct 133 ms 21336 KB Output is correct
63 Correct 131 ms 21200 KB Output is correct
64 Correct 180 ms 21248 KB Output is correct
65 Correct 142 ms 21316 KB Output is correct
66 Correct 142 ms 21304 KB Output is correct
67 Correct 143 ms 21244 KB Output is correct
68 Correct 49 ms 21328 KB Output is correct
69 Correct 49 ms 21296 KB Output is correct
70 Correct 37 ms 21264 KB Output is correct
71 Correct 45 ms 21320 KB Output is correct
72 Correct 35 ms 21320 KB Output is correct
73 Correct 32 ms 21536 KB Output is correct
74 Correct 56 ms 21600 KB Output is correct
75 Correct 71 ms 21556 KB Output is correct
76 Correct 81 ms 21572 KB Output is correct
77 Correct 79 ms 21508 KB Output is correct
78 Correct 84 ms 21452 KB Output is correct
79 Correct 51 ms 21552 KB Output is correct
80 Correct 65 ms 21480 KB Output is correct
81 Correct 103 ms 21564 KB Output is correct
82 Correct 60 ms 21500 KB Output is correct
83 Correct 83 ms 21448 KB Output is correct
84 Correct 72 ms 21556 KB Output is correct
85 Correct 83 ms 21452 KB Output is correct
86 Correct 85 ms 21512 KB Output is correct
87 Correct 75 ms 21444 KB Output is correct
88 Correct 95 ms 21464 KB Output is correct
89 Correct 86 ms 21464 KB Output is correct
90 Correct 92 ms 21348 KB Output is correct
91 Correct 86 ms 21376 KB Output is correct
92 Correct 89 ms 21468 KB Output is correct