oj.uz

Submission #995740

# Submission time Handle Problem Language Result Execution time Memory
995740 2024-06-09T20:41:28 Z MilosMilutinovic Pipes (BOI13_pipes) C++14
74.0741 / 100
 97 ms 19652 KB 
#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  vector<long long> a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  vector<vector<array<int, 2>>> g(n);
  for (int i = 0; i < m; i++) {
    int x, y;
    cin >> x >> y;
    --x; --y;
    g[x].push_back({y, i});
    g[y].push_back({x, i});
  }
  if (m > n) {
    cout << 0 << '\n';
    return 0;
  }
  if (n == 1) {
    cout << 2 * a[0] << '\n';
    return 0;
  }
  if (m < n) {
    vector<long long> res(m);
    function<void(int, int)> Dfs = [&](int v, int pv) {
      for (auto& e : g[v]) {
        int u = e[0];
        if (u == pv) {
          continue;
        }
        Dfs(u, v);
        if (a[u] != 0) {
          res[e[1]] = 2 * a[u];
          a[v] -= a[u];
        }
      }
    };
    Dfs(0, 0);
    if (a[0] != 0) {
      cout << 0 << '\n';
      return 0;
    }
    for (int i = 0; i < m; i++) {
      cout << res[i] << '\n';
    }
    return 0;
  }
  vector<int> deg(n);
  for (int i = 0; i < n; i++) {
    deg[i] = (int) g[i].size();
  }
  vector<int> que;
  for (int i = 0; i < n; i++) {
    if (deg[i] == 1) {
      que.push_back(i);
    }
  }
  auto orig = a;
  vector<long long> res(m);
  for (int b = 0; b < (int) que.size(); b++) {
    int i = que[b];
    for (auto& e : g[i]) {
      int j = e[0];
      deg[j] -= 1;
      if (deg[j] == 1) {
        que.push_back(j);
        res[e[1]] = 2 * a[i];
        a[j] -= a[i];
      }
    }
  }
  vector<int> cyc;
  for (int i = 0; i < n; i++) {
    if (deg[i] > 1) {
      cyc.push_back(i);
    }
  }
  if ((int) cyc.size() % 2 == 0) {
    cout << 0 << '\n';
    return 0;
  }
  vector<bool> was(n);
  vector<long long> vals;
  vector<int> ids;
  function<void(int)> Dfs = [&](int v) {
    was[v] = true;
    vals.push_back(a[v]);
    int back = -1;
    bool found = false;
    for (auto& e : g[v]) {
      int u = e[0];
      int i = e[1];
      if (u == cyc[0]) {
        back = i;
      }
      if (was[u] || deg[u] <= 1) {
        continue;
      }
      found = true;
      ids.push_back(i);
      Dfs(u);
    }
    if (!found) {
      ids.push_back(back);
    }
  }; 
  Dfs(cyc[0]);
  long long total = 0;
  for (int i = 0; i < (int) vals.size(); i++) {
    total = vals[i] - total;
  }
  if (ids.empty()) {
    while (true) {

    }
  }
  assert((int) ids.size() == vals.size());
  res[ids.back()] = 2 * total;
  for (int i = 0; i < n; i++) {
    for (auto& p : g[i]) {
      if (p[1] == ids.back()) {
        a[i] -= total;
      }
    }
  }
  was = vector<bool>(n, false);
  Dfs = [&](int v) {
    was[v] = true;
    for (auto& p : g[v]) {
      int u = p[0];
      int i = p[1];
      if (deg[u] <= 1 || was[u]) {
        continue;
      }
      Dfs(u);
      res[i] = 2 * a[u];
      a[v] -= a[u];
    }
  };
  Dfs(cyc.back());
  if (a != vector<long long>(n, 0LL)) {
    cout << 0 << '\n';
    return 0;
  }
  for (int i = 0; i < m; i++) {
    cout << res[i] << '\n';
  }
  return 0;
}

Compilation message

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from pipes.cpp:1:
pipes.cpp: In function 'int main()':
pipes.cpp:124:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  124 |   assert((int) ids.size() == vals.size());
      |          ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 33 ms 8264 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 30 ms 6840 KB Output is correct
14 Correct 32 ms 8020 KB Output is correct
15 Correct 33 ms 8532 KB Output is correct
16 Correct 39 ms 7508 KB Output is correct
17 Correct 39 ms 8272 KB Output is correct
18 Correct 33 ms 8532 KB Output is correct
19 Correct 37 ms 12368 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 34 ms 8412 KB Output is correct
23 Correct 26 ms 6748 KB Output is correct
24 Correct 36 ms 8336 KB Output is correct
25 Correct 28 ms 7008 KB Output is correct

Subtask #2
44.0740740741 / 70.0

# Verdict Execution time Memory Grader output
1 Incorrect 0 ms 344 KB Output isn't correct
2 Incorrect 1 ms 604 KB Output isn't correct
3 Correct 26 ms 9000 KB Output is correct
4 Correct 23 ms 6748 KB Output is correct
5 Correct 29 ms 6864 KB Output is correct
6 Correct 90 ms 17312 KB Output is correct
7 Incorrect 0 ms 348 KB Output isn't correct
8 Incorrect 0 ms 348 KB Output isn't correct
9 Correct 1 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 344 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Incorrect 0 ms 348 KB Output isn't correct
15 Incorrect 1 ms 760 KB Output isn't correct
16 Incorrect 1 ms 348 KB Output isn't correct
17 Correct 0 ms 600 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 1 ms 464 KB Output is correct
20 Correct 1 ms 348 KB Output is correct
21 Correct 1 ms 348 KB Output is correct
22 Incorrect 1 ms 348 KB Output isn't correct
23 Incorrect 34 ms 14008 KB Output isn't correct
24 Incorrect 39 ms 15952 KB Output isn't correct
25 Correct 29 ms 9060 KB Output is correct
26 Correct 32 ms 6740 KB Output is correct
27 Correct 26 ms 6492 KB Output is correct
28 Correct 29 ms 7008 KB Output is correct
29 Correct 78 ms 14724 KB Output is correct
30 Incorrect 36 ms 14668 KB Output isn't correct
31 Incorrect 42 ms 19652 KB Output isn't correct
32 Incorrect 35 ms 12236 KB Output isn't correct
33 Correct 28 ms 9396 KB Output is correct
34 Correct 22 ms 6748 KB Output is correct
35 Correct 24 ms 6856 KB Output is correct
36 Correct 30 ms 7244 KB Output is correct
37 Correct 97 ms 17276 KB Output is correct
38 Incorrect 39 ms 14928 KB Output isn't correct
39 Incorrect 30 ms 11464 KB Output isn't correct
40 Incorrect 37 ms 15440 KB Output isn't correct
41 Correct 26 ms 9428 KB Output is correct
42 Correct 23 ms 6620 KB Output is correct
43 Correct 24 ms 6484 KB Output is correct
44 Correct 28 ms 7004 KB Output is correct
45 Correct 77 ms 14368 KB Output is correct
46 Incorrect 36 ms 14416 KB Output isn't correct
47 Incorrect 38 ms 15644 KB Output isn't correct
48 Incorrect 39 ms 19276 KB Output isn't correct
49 Correct 26 ms 9260 KB Output is correct
50 Correct 23 ms 6736 KB Output is correct
51 Correct 24 ms 7004 KB Output is correct
52 Correct 24 ms 6744 KB Output is correct
53 Correct 77 ms 14424 KB Output is correct
54 Incorrect 34 ms 13900 KB Output isn't correct