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Submission #511174

# Submission time Handle Problem Language Result Execution time Memory
511174 2022-01-15T10:38:48 Z 600Mihnea Mecho (IOI09_mecho) C++17
100 / 100
 182 ms 16016 KB 
#include <bits/stdc++.h>

using namespace std;

const int N = 1000 + 7;
const int INF = (int) 1e9 + 7;
int dr[] = {-1, 0, 1, 0};
int dc[] = {0, 1, 0, -1};
int n;
int speed;
int r1, c1;
int r2, c2;
int a[N][N];
int dist_m[N][N];
int dist_b[N][N];

vector<pair<int, int>> ord;

void compute(int dist[N][N], vector<pair<int, int>> init) {
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      dist[i][j] = INF;
    }
  }

  queue<pair<int, int>> q;
  for (auto &it : init) {
    dist[it.first][it.second] = 0;
    q.push(it);
  }
  while (!q.empty()) {
    auto it = q.front();
    int r = it.first;
    int c = it.second;
    ord.push_back(it);
    q.pop();
    for (int k = 0; k < 4; k++) {
      int rn = r + dr[k];
      int cn = c + dc[k];
      if (a[rn][cn] && dist[rn][cn] == INF) {
        dist[rn][cn] = 1 + dist[r][c];
        q.push({rn, cn});
      }
    }
  }
}

int dist[N][N];
bool ok[N][N];

signed main() {
  ios::sync_with_stdio(0); cin.tie(0);

///  freopen ("input", "r", stdin);

  cin >> n >> speed;

  vector<pair<int, int>> bees;

  for (int i = 1; i <= n; i++) {
    string s;
    cin >> s;
    for (int j = 1; j <= n; j++) {
      char ch = s[j - 1];
      if (ch == 'T') {
        a[i][j] = 0;
        continue;
      }
      if (ch == 'G') {
        a[i][j] = 1;
        continue;
      }
      if (ch == 'M') {
        r1 = i;
        c1 = j;
        continue;
      }
      if (ch == 'D') {
        r2 = i;
        c2 = j;
        continue;
      }
      if (ch == 'H') {
        bees.push_back({i, j});
        continue;
      }
    }
  }
  ///cout << r2 << " " << c2 << "\n";
  vector<pair<int, int>> m;
  m.push_back({r1, c1});
  a[r1][c1] = 1;
  compute(dist_b, bees);
  ord.clear();
  a[r2][c2] = 1;
  compute(dist_m, m);

  int low = 0, high = dist_b[r1][c1] - 1, sol = -1;

  while (low <= high) {
    int stay = (low + high) / 2;
    ///stay = 5;
  ///  stay = 1;
    ///stay = 3;
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= n; j++) {
        ok[i][j] = 0;
      }
    }
    ok[r1][c1] = 1;
    queue<pair<int, int>> q;
    q.push({r1, c1});
    while (!q.empty()) {
      int r = q.front().first, c = q.front().second;
      q.pop();
      if (ok[r][c]) {
        for (int k = 0; k < 4; k++) {
          int rn = r + dr[k];
          int cn = c + dc[k];
          int the_dist = dist_m[r][c] + 1;
          if (ok[rn][cn] || a[rn][cn] == 0) continue;

          dist_m[rn][cn] = the_dist;
          ok[rn][cn] |= ((stay + the_dist / speed) < (dist_b[rn][cn] + (rn == r2 && cn == c2)));
          if (ok[rn][cn]) q.push({rn, cn});
        }
      }
    }
//    cout << " val = " << ok[r2][c2 - 1] << "\n";
 //   exit(0);
 if (0) {
    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= n; j++) {
        if (ok[i][j]) {
          if ((stay + (dist_m[i][j] + speed - 1) / speed) > INF / 10 && 0) {
            cout << "? ";
          } else {
            cout << (stay + (dist_m[i][j] + speed - 1) / speed) << " ";
          }
        } else {
          cout << "- ";
        }
        ///cout << ok[i][j] << " ";
      }
      cout << "\n";
    }
    cout << "\n";

    for (int i = 1; i <= n; i++) {
      for (int j = 1; j <= n; j++) {
        if (ok[i][j]) {
          if (dist_b[i][j] > INF / 10) {
            cout << "? ";
          } else {
            cout << dist_b[i][j] << " ";
          }
        } else {
          cout << "- ";
        }
        ///cout << ok[i][j] << " ";
      }
      cout << "\n";
    }

    exit(0);}
    if (ok[r2][c2]) {
      sol = stay;
      low = stay + 1;
    } else {
      high = stay - 1;
    }
  }

  cout << sol << "\n";
  return 0;
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= n; j++) {
      int val = dist_m[i][j];
      if (val == INF) {
        cout << "- ";
      } else {
        cout << val << " ";
      }
    }
    cout << "\n";
  }

  return 0;
}

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 0 ms 332 KB Output is correct
3 Correct 0 ms 332 KB Output is correct
4 Correct 0 ms 332 KB Output is correct
5 Correct 0 ms 332 KB Output is correct
6 Correct 0 ms 460 KB Output is correct
7 Correct 100 ms 15764 KB Output is correct
8 Correct 1 ms 460 KB Output is correct
9 Correct 1 ms 460 KB Output is correct
10 Correct 0 ms 460 KB Output is correct
11 Correct 0 ms 460 KB Output is correct
12 Correct 1 ms 1100 KB Output is correct
13 Correct 1 ms 972 KB Output is correct
14 Correct 1 ms 1100 KB Output is correct
15 Correct 1 ms 588 KB Output is correct
16 Correct 1 ms 588 KB Output is correct
17 Correct 1 ms 588 KB Output is correct
18 Correct 0 ms 588 KB Output is correct
19 Correct 1 ms 716 KB Output is correct
20 Correct 1 ms 716 KB Output is correct
21 Correct 1 ms 844 KB Output is correct
22 Correct 1 ms 844 KB Output is correct
23 Correct 1 ms 972 KB Output is correct
24 Correct 1 ms 972 KB Output is correct
25 Correct 1 ms 1100 KB Output is correct
26 Correct 1 ms 1100 KB Output is correct
27 Correct 1 ms 1100 KB Output is correct
28 Correct 1 ms 1100 KB Output is correct
29 Correct 1 ms 1228 KB Output is correct
30 Correct 1 ms 1228 KB Output is correct
31 Correct 2 ms 1356 KB Output is correct
32 Correct 2 ms 1228 KB Output is correct
33 Correct 6 ms 5324 KB Output is correct
34 Correct 6 ms 5324 KB Output is correct
35 Correct 17 ms 5576 KB Output is correct
36 Correct 9 ms 6216 KB Output is correct
37 Correct 8 ms 6216 KB Output is correct
38 Correct 27 ms 6472 KB Output is correct
39 Correct 9 ms 6980 KB Output is correct
40 Correct 11 ms 6980 KB Output is correct
41 Correct 31 ms 7456 KB Output is correct
42 Correct 11 ms 7852 KB Output is correct
43 Correct 11 ms 7880 KB Output is correct
44 Correct 38 ms 8264 KB Output is correct
45 Correct 14 ms 8724 KB Output is correct
46 Correct 12 ms 8716 KB Output is correct
47 Correct 46 ms 9284 KB Output is correct
48 Correct 17 ms 9536 KB Output is correct
49 Correct 17 ms 9596 KB Output is correct
50 Correct 63 ms 10240 KB Output is correct
51 Correct 23 ms 10500 KB Output is correct
52 Correct 18 ms 10420 KB Output is correct
53 Correct 63 ms 11320 KB Output is correct
54 Correct 24 ms 11296 KB Output is correct
55 Correct 18 ms 11336 KB Output is correct
56 Correct 80 ms 12304 KB Output is correct
57 Correct 22 ms 12220 KB Output is correct
58 Correct 22 ms 12220 KB Output is correct
59 Correct 92 ms 13376 KB Output is correct
60 Correct 26 ms 13260 KB Output is correct
61 Correct 26 ms 13204 KB Output is correct
62 Correct 116 ms 14388 KB Output is correct
63 Correct 113 ms 13720 KB Output is correct
64 Correct 182 ms 13620 KB Output is correct
65 Correct 177 ms 13652 KB Output is correct
66 Correct 134 ms 13724 KB Output is correct
67 Correct 120 ms 13620 KB Output is correct
68 Correct 69 ms 13748 KB Output is correct
69 Correct 58 ms 13680 KB Output is correct
70 Correct 63 ms 13720 KB Output is correct
71 Correct 52 ms 13680 KB Output is correct
72 Correct 50 ms 13724 KB Output is correct
73 Correct 50 ms 15888 KB Output is correct
74 Correct 69 ms 15908 KB Output is correct
75 Correct 65 ms 16016 KB Output is correct
76 Correct 67 ms 15836 KB Output is correct
77 Correct 67 ms 15924 KB Output is correct
78 Correct 95 ms 15912 KB Output is correct
79 Correct 58 ms 15888 KB Output is correct
80 Correct 75 ms 15880 KB Output is correct
81 Correct 70 ms 15824 KB Output is correct
82 Correct 64 ms 15912 KB Output is correct
83 Correct 83 ms 15808 KB Output is correct
84 Correct 70 ms 15824 KB Output is correct
85 Correct 78 ms 15800 KB Output is correct
86 Correct 83 ms 15796 KB Output is correct
87 Correct 75 ms 15820 KB Output is correct
88 Correct 93 ms 15676 KB Output is correct
89 Correct 82 ms 15760 KB Output is correct
90 Correct 88 ms 15640 KB Output is correct
91 Correct 88 ms 15652 KB Output is correct
92 Correct 92 ms 15708 KB Output is correct