Submission #995737

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
995737	2024-06-09T20:38:15 Z	MilosMilutinovic	Pipes (BOI13_pipes)	C++14	74.0741 / 100	93 ms	19652 KB

pipes

#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;
  }
  res[ids.back()] = 2 * total;
  for (int i = 0; i < n; i++) {
    for (auto& p : g[i]) {
      if (p[2] == 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	0 ms	344 KB	Output is correct
2	Correct	1 ms	852 KB	Output is correct
3	Correct	1 ms	348 KB	Output is correct
4	Correct	34 ms	8416 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	6804 KB	Output is correct
14	Correct	35 ms	7968 KB	Output is correct
15	Correct	32 ms	8420 KB	Output is correct
16	Correct	28 ms	7268 KB	Output is correct
17	Correct	32 ms	8504 KB	Output is correct
18	Correct	33 ms	8364 KB	Output is correct
19	Correct	35 ms	12368 KB	Output is correct
20	Correct	1 ms	344 KB	Output is correct
21	Correct	1 ms	344 KB	Output is correct
22	Correct	32 ms	8380 KB	Output is correct
23	Correct	26 ms	6748 KB	Output is correct
24	Correct	38 ms	8352 KB	Output is correct
25	Correct	27 ms	6996 KB	Output is correct

Subtask #2

44.0740740741 / 70.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	0 ms	348 KB	Output isn't correct
2	Incorrect	1 ms	604 KB	Output isn't correct
3	Correct	25 ms	9048 KB	Output is correct
4	Correct	26 ms	6748 KB	Output is correct
5	Correct	23 ms	7004 KB	Output is correct
6	Correct	91 ms	17232 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	348 KB	Output is correct
12	Correct	0 ms	348 KB	Output is correct
13	Correct	0 ms	344 KB	Output is correct
14	Incorrect	0 ms	348 KB	Output isn't correct
15	Incorrect	0 ms	604 KB	Output isn't correct
16	Incorrect	0 ms	348 KB	Output isn't correct
17	Correct	1 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	1 ms	348 KB	Output isn't correct
23	Incorrect	31 ms	14028 KB	Output isn't correct
24	Incorrect	37 ms	15952 KB	Output isn't correct
25	Correct	30 ms	9156 KB	Output is correct
26	Correct	23 ms	6640 KB	Output is correct
27	Correct	22 ms	6564 KB	Output is correct
28	Correct	25 ms	7000 KB	Output is correct
29	Correct	78 ms	14672 KB	Output is correct
30	Incorrect	49 ms	14732 KB	Output isn't correct
31	Incorrect	43 ms	19652 KB	Output isn't correct
32	Incorrect	33 ms	12232 KB	Output isn't correct
33	Correct	26 ms	9424 KB	Output is correct
34	Correct	23 ms	6740 KB	Output is correct
35	Correct	24 ms	6756 KB	Output is correct
36	Correct	24 ms	7004 KB	Output is correct
37	Correct	93 ms	17200 KB	Output is correct
38	Incorrect	37 ms	14948 KB	Output isn't correct
39	Incorrect	43 ms	11336 KB	Output isn't correct
40	Incorrect	36 ms	15376 KB	Output isn't correct
41	Correct	25 ms	9264 KB	Output is correct
42	Correct	24 ms	6492 KB	Output is correct
43	Correct	25 ms	6492 KB	Output is correct
44	Correct	25 ms	6996 KB	Output is correct
45	Correct	70 ms	14288 KB	Output is correct
46	Incorrect	35 ms	14256 KB	Output isn't correct
47	Incorrect	35 ms	15524 KB	Output isn't correct
48	Incorrect	39 ms	19144 KB	Output isn't correct
49	Correct	27 ms	9168 KB	Output is correct
50	Correct	34 ms	6776 KB	Output is correct
51	Correct	23 ms	7000 KB	Output is correct
52	Correct	23 ms	6748 KB	Output is correct
53	Correct	76 ms	14444 KB	Output is correct
54	Incorrect	36 ms	13908 KB	Output isn't correct