oj.uz

Submission #995748

# Submission time Handle Problem Language Result Execution time Memory
995748 2024-06-09T21:01:42 Z MilosMilutinovic Pipes (BOI13_pipes) C++14
79.2593 / 100
 96 ms 19660 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];
        a[i] = 0;
      }
    }
  }
  vector<int> cyc;
  for (int i = 0; i < n; i++) {
    if (deg[i] > 1) {
      cyc.push_back(i);
    }
  }
  for (int i : cyc) {
    for (auto& e : g[i]) {
      int j = e[0];
      if (deg[j] < 2) {
        res[e[1]] = 2 * a[j];
        a[i] -= a[j];
        a[j] = 0;
      }
    }
  }
  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 (total % 2 == 1) {
    cout << 0 << '\n';
    return 0;
  }
  total /= 2;
  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] || i == ids.back()) {
        continue;
      }
      Dfs(u);
      res[i] = 2 * a[u];
      a[v] -= a[u];
      a[u] = 0;
    }
  };
  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;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 344 KB Output is correct
2 Correct 1 ms 344 KB Output is correct
3 Correct 1 ms 348 KB Output is correct
4 Correct 34 ms 8484 KB Output is correct
5 Correct 1 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 0 ms 348 KB Output is correct
10 Correct 0 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 27 ms 6888 KB Output is correct
14 Correct 33 ms 8020 KB Output is correct
15 Correct 33 ms 8540 KB Output is correct
16 Correct 30 ms 7252 KB Output is correct
17 Correct 32 ms 8416 KB Output is correct
18 Correct 32 ms 8532 KB Output is correct
19 Correct 34 ms 12372 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 33 ms 8380 KB Output is correct
23 Correct 33 ms 6696 KB Output is correct
24 Correct 32 ms 8528 KB Output is correct
25 Correct 31 ms 6996 KB Output is correct

Subtask #2
49.2592592593 / 70.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 348 KB Output isn't correct
2 Incorrect 1 ms 392 KB Output isn't correct
3 Correct 28 ms 9076 KB Output is correct
4 Correct 34 ms 6688 KB Output is correct
5 Correct 25 ms 6992 KB Output is correct
6 Correct 94 ms 17236 KB Output is correct
7 Incorrect 0 ms 348 KB Output isn't correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 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 600 KB Output isn't correct
16 Correct 1 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 0 ms 348 KB Output is correct
19 Correct 0 ms 348 KB Output is correct
20 Correct 0 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 30 ms 13148 KB Output isn't correct
24 Incorrect 40 ms 15952 KB Output isn't correct
25 Correct 34 ms 9172 KB Output is correct
26 Correct 26 ms 6716 KB Output is correct
27 Correct 25 ms 6480 KB Output is correct
28 Correct 24 ms 6992 KB Output is correct
29 Correct 78 ms 14676 KB Output is correct
30 Correct 51 ms 14668 KB Output is correct
31 Incorrect 53 ms 19660 KB Output isn't correct
32 Incorrect 33 ms 12236 KB Output isn't correct
33 Correct 28 ms 9432 KB Output is correct
34 Correct 22 ms 6748 KB Output is correct
35 Correct 24 ms 6764 KB Output is correct
36 Correct 26 ms 7000 KB Output is correct
37 Correct 96 ms 17232 KB Output is correct
38 Incorrect 37 ms 14928 KB Output isn't correct
39 Incorrect 33 ms 11468 KB Output isn't correct
40 Incorrect 36 ms 15308 KB Output isn't correct
41 Correct 26 ms 9320 KB Output is correct
42 Correct 25 ms 6576 KB Output is correct
43 Correct 23 ms 6744 KB Output is correct
44 Correct 23 ms 7004 KB Output is correct
45 Correct 72 ms 14296 KB Output is correct
46 Incorrect 36 ms 14408 KB Output isn't correct
47 Incorrect 35 ms 15580 KB Output isn't correct
48 Incorrect 41 ms 19140 KB Output isn't correct
49 Correct 28 ms 9160 KB Output is correct
50 Correct 24 ms 6748 KB Output is correct
51 Correct 24 ms 6820 KB Output is correct
52 Correct 23 ms 6748 KB Output is correct
53 Correct 79 ms 14556 KB Output is correct
54 Correct 41 ms 13904 KB Output is correct