Submission #254311

# Submission time Handle Problem Language Result Execution time Memory
254311 2020-07-29T20:20:19 Z sandoval Mecho (IOI09_mecho) C++11
11 / 100
209 ms 9468 KB
#include <bits/stdc++.h>

using namespace std;
using ii = pair<int,int>;
using ll = long long;

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

constexpr int MAXS = 5+800;
constexpr int INF = 1e8;
char c[MAXS][MAXS];
int N,S, tb[MAXS][MAXS];

bool ok(int x, int y) {
  return x >= 0 && y >= 0 && x < N && y < N;
}

void bfs_bees() {
  queue<ii> q;
  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < N; ++j) {
      if (c[i][j] == 'H') {
        q.push({i,j});
        tb[i][j] = 0;
      } else {
        tb[i][j] = INF;
      }
    }
  }

  while (!q.empty()) {
    auto u = q.front(); q.pop();
    for (int k = 0; k < 4; ++k) {
      int newx = u.first+dx[k], newy = u.second+dy[k];
      if (ok(newx, newy) && 1+tb[u.first][u.second] < tb[newx][newy] && c[newx][newy] == 'G') {
        q.push({newx, newy});
        tb[newx][newy] = 1+tb[u.first][u.second];
      }
    }
  }
}


ii dist[MAXS][MAXS];
bool can(const ii& source, const ii& target, int t) {
  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < N; ++j) {
      dist[i][j] = {10*INF, 0};
    }
  }

  queue<array<int,2>> q; q.push({source.first, source.second});
  dist[source.first][source.second] = {t, S};

  while (!q.empty()) {
    auto u = q.front(); q.pop();
    if (u[0] == target.first && u[1] == target.second) return true;
    for (int k = 0; k < 4; ++k) {
      int newx = u[0]+dx[k], newy = u[1]+dy[k];
      ii newcost = dist[u[0]][u[1]];
      newcost.second--;

      if (newcost.second < 0) {
        assert(newcost.second == -1);
        newcost.first++;
        newcost.second = S;
      }

      if (ok(newx, newy) && (c[newx][newy] == 'G' || c[newx][newy] == 'D') && (newcost.first < tb[newx][newy]) &&
         (newcost.first < dist[newx][newy].first || (newcost.first == dist[newx][newy].first && newcost.second > dist[newx][newy].second))) {
        q.push({newx, newy});
        dist[newx][newy] = newcost;
      }
    }
  }
  return false;
}

int main() {
  ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
  cin >> N >> S;
  ii start, target;
  for (int i = 0; i < N; ++i) {
    for (int j = 0; j < N; ++j) {
      cin >> c[i][j];
      if (c[i][j] == 'M') {
        start = {i,j};
      } else if (c[i][j] == 'D') {
        target = {i,j};
      }
    }
  }

  bfs_bees();

  int low = 0, high = INF, best = -1;
  while (low <= high) {
    int mid = (low+high) >> 1;
    if (can(start, target, mid)) {
      low = 1+mid;
      best = mid;
    } else {
      high = mid-1;
    }
  }
  cout << best << '\n';
  return 0;
}
# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 384 KB Output isn't correct
2 Incorrect 1 ms 384 KB Output isn't correct
3 Incorrect 1 ms 384 KB Output isn't correct
4 Incorrect 1 ms 384 KB Output isn't correct
5 Correct 0 ms 256 KB Output is correct
6 Incorrect 1 ms 384 KB Output isn't correct
7 Incorrect 129 ms 9468 KB Output isn't correct
8 Incorrect 1 ms 512 KB Output isn't correct
9 Correct 0 ms 512 KB Output is correct
10 Incorrect 1 ms 512 KB Output isn't correct
11 Incorrect 0 ms 512 KB Output isn't correct
12 Incorrect 1 ms 896 KB Output isn't correct
13 Incorrect 1 ms 768 KB Output isn't correct
14 Incorrect 1 ms 896 KB Output isn't correct
15 Incorrect 0 ms 512 KB Output isn't correct
16 Correct 1 ms 512 KB Output is correct
17 Incorrect 1 ms 512 KB Output isn't correct
18 Correct 1 ms 512 KB Output is correct
19 Incorrect 1 ms 640 KB Output isn't correct
20 Correct 1 ms 640 KB Output is correct
21 Incorrect 1 ms 640 KB Output isn't correct
22 Correct 1 ms 640 KB Output is correct
23 Incorrect 1 ms 768 KB Output isn't correct
24 Correct 1 ms 768 KB Output is correct
25 Incorrect 1 ms 896 KB Output isn't correct
26 Correct 1 ms 896 KB Output is correct
27 Incorrect 1 ms 896 KB Output isn't correct
28 Correct 1 ms 896 KB Output is correct
29 Incorrect 1 ms 896 KB Output isn't correct
30 Correct 1 ms 896 KB Output is correct
31 Incorrect 1 ms 1024 KB Output isn't correct
32 Correct 1 ms 1024 KB Output is correct
33 Incorrect 8 ms 4096 KB Output isn't correct
34 Correct 8 ms 4096 KB Output is correct
35 Correct 25 ms 4096 KB Output is correct
36 Incorrect 10 ms 4608 KB Output isn't correct
37 Correct 15 ms 4608 KB Output is correct
38 Correct 37 ms 4608 KB Output is correct
39 Incorrect 18 ms 5120 KB Output isn't correct
40 Correct 12 ms 5120 KB Output is correct
41 Correct 43 ms 5240 KB Output is correct
42 Incorrect 14 ms 5760 KB Output isn't correct
43 Correct 14 ms 5760 KB Output is correct
44 Correct 58 ms 5880 KB Output is correct
45 Incorrect 17 ms 6272 KB Output isn't correct
46 Correct 16 ms 6272 KB Output is correct
47 Correct 68 ms 6300 KB Output is correct
48 Incorrect 20 ms 6912 KB Output isn't correct
49 Correct 20 ms 6904 KB Output is correct
50 Correct 81 ms 6808 KB Output is correct
51 Incorrect 22 ms 7424 KB Output isn't correct
52 Correct 24 ms 7424 KB Output is correct
53 Correct 95 ms 7424 KB Output is correct
54 Incorrect 27 ms 8064 KB Output isn't correct
55 Correct 26 ms 8056 KB Output is correct
56 Correct 114 ms 8184 KB Output is correct
57 Incorrect 29 ms 8576 KB Output isn't correct
58 Correct 32 ms 8568 KB Output is correct
59 Correct 133 ms 8568 KB Output is correct
60 Incorrect 32 ms 9208 KB Output isn't correct
61 Correct 36 ms 9216 KB Output is correct
62 Correct 184 ms 9208 KB Output is correct
63 Incorrect 181 ms 9216 KB Output isn't correct
64 Correct 159 ms 9216 KB Output is correct
65 Incorrect 209 ms 9212 KB Output isn't correct
66 Incorrect 160 ms 9208 KB Output isn't correct
67 Incorrect 185 ms 9216 KB Output isn't correct
68 Incorrect 65 ms 9336 KB Output isn't correct
69 Correct 59 ms 9212 KB Output is correct
70 Incorrect 62 ms 9208 KB Output isn't correct
71 Incorrect 61 ms 9208 KB Output isn't correct
72 Incorrect 56 ms 9208 KB Output isn't correct
73 Incorrect 99 ms 9312 KB Output isn't correct
74 Correct 92 ms 9312 KB Output is correct
75 Incorrect 101 ms 9368 KB Output isn't correct
76 Incorrect 115 ms 9316 KB Output isn't correct
77 Incorrect 117 ms 9316 KB Output isn't correct
78 Incorrect 100 ms 9340 KB Output isn't correct
79 Correct 79 ms 9468 KB Output is correct
80 Incorrect 83 ms 9348 KB Output isn't correct
81 Incorrect 85 ms 9468 KB Output isn't correct
82 Incorrect 84 ms 9348 KB Output isn't correct
83 Incorrect 137 ms 9376 KB Output isn't correct
84 Correct 114 ms 9352 KB Output is correct
85 Incorrect 115 ms 9380 KB Output isn't correct
86 Incorrect 139 ms 9248 KB Output isn't correct
87 Correct 134 ms 9248 KB Output is correct
88 Incorrect 124 ms 9300 KB Output isn't correct
89 Correct 117 ms 9428 KB Output is correct
90 Correct 124 ms 9308 KB Output is correct
91 Correct 167 ms 9300 KB Output is correct
92 Incorrect 166 ms 9428 KB Output isn't correct