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Submission #995741

# Submission time Handle Problem Language Result Execution time Memory
995741 2024-06-09T20:42:35 Z MilosMilutinovic Pipes (BOI13_pipes) C++14
74.0741 / 100
 92 ms 19656 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) {

    }
  }
  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]) {
        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;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 33 ms 8284 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 0 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 348 KB Output is correct
13 Correct 30 ms 6740 KB Output is correct
14 Correct 34 ms 8016 KB Output is correct
15 Correct 32 ms 8528 KB Output is correct
16 Correct 28 ms 7260 KB Output is correct
17 Correct 33 ms 8272 KB Output is correct
18 Correct 33 ms 8376 KB Output is correct
19 Correct 37 ms 12592 KB Output is correct
20 Correct 0 ms 348 KB Output is correct
21 Correct 0 ms 348 KB Output is correct
22 Correct 40 ms 8412 KB Output is correct
23 Correct 26 ms 6748 KB Output is correct
24 Correct 37 ms 8356 KB Output is correct
25 Correct 29 ms 6992 KB Output is correct

Subtask #2
44.0740740741 / 70.0

# Verdict Execution time Memory Grader output
1 Incorrect 1 ms 344 KB Output isn't correct
2 Incorrect 1 ms 604 KB Output isn't correct
3 Correct 29 ms 8960 KB Output is correct
4 Correct 23 ms 6716 KB Output is correct
5 Correct 27 ms 6808 KB Output is correct
6 Correct 91 ms 17236 KB Output is correct
7 Incorrect 0 ms 344 KB Output isn't correct
8 Incorrect 0 ms 344 KB Output isn't correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 0 ms 344 KB Output is correct
13 Correct 1 ms 348 KB Output is correct
14 Incorrect 0 ms 348 KB Output isn't correct
15 Incorrect 1 ms 604 KB Output isn't correct
16 Incorrect 1 ms 348 KB Output isn't correct
17 Correct 0 ms 348 KB Output is correct
18 Correct 1 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 0 ms 348 KB Output isn't correct
23 Incorrect 32 ms 13364 KB Output isn't correct
24 Incorrect 39 ms 15192 KB Output isn't correct
25 Correct 28 ms 9148 KB Output is correct
26 Correct 29 ms 6748 KB Output is correct
27 Correct 27 ms 6480 KB Output is correct
28 Correct 29 ms 6996 KB Output is correct
29 Correct 86 ms 14692 KB Output is correct
30 Incorrect 34 ms 14552 KB Output isn't correct
31 Incorrect 39 ms 19656 KB Output isn't correct
32 Incorrect 32 ms 12156 KB Output isn't correct
33 Correct 27 ms 9420 KB Output is correct
34 Correct 23 ms 6748 KB Output is correct
35 Correct 27 ms 6748 KB Output is correct
36 Correct 28 ms 7032 KB Output is correct
37 Correct 92 ms 17240 KB Output is correct
38 Incorrect 38 ms 14928 KB Output isn't correct
39 Incorrect 30 ms 11468 KB Output isn't correct
40 Incorrect 36 ms 14668 KB Output isn't correct
41 Correct 25 ms 9420 KB Output is correct
42 Correct 28 ms 6744 KB Output is correct
43 Correct 24 ms 6748 KB Output is correct
44 Correct 24 ms 7004 KB Output is correct
45 Correct 71 ms 14420 KB Output is correct
46 Incorrect 40 ms 14408 KB Output isn't correct
47 Incorrect 36 ms 14668 KB Output isn't correct
48 Incorrect 38 ms 19356 KB Output isn't correct
49 Correct 29 ms 9172 KB Output is correct
50 Correct 29 ms 6736 KB Output is correct
51 Correct 23 ms 7004 KB Output is correct
52 Correct 23 ms 6736 KB Output is correct
53 Correct 76 ms 14416 KB Output is correct
54 Incorrect 35 ms 13904 KB Output isn't correct