Submission #995744

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
995744	2024-06-09T20:54:45 Z	MilosMilutinovic	Pipes (BOI13_pipes)	C++14	74.0741 / 100	105 ms	19660 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;
  }
  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	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	34 ms	8300 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	0 ms	348 KB	Output is correct
12	Correct	1 ms	348 KB	Output is correct
13	Correct	30 ms	6744 KB	Output is correct
14	Correct	31 ms	7972 KB	Output is correct
15	Correct	34 ms	8480 KB	Output is correct
16	Correct	27 ms	7260 KB	Output is correct
17	Correct	33 ms	8372 KB	Output is correct
18	Correct	36 ms	8532 KB	Output is correct
19	Correct	36 ms	12632 KB	Output is correct
20	Correct	0 ms	348 KB	Output is correct
21	Correct	1 ms	348 KB	Output is correct
22	Correct	43 ms	8356 KB	Output is correct
23	Correct	26 ms	6776 KB	Output is correct
24	Correct	34 ms	8536 KB	Output is correct
25	Correct	29 ms	7092 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	0 ms	604 KB	Output isn't correct
3	Correct	35 ms	9040 KB	Output is correct
4	Correct	25 ms	6748 KB	Output is correct
5	Correct	23 ms	6988 KB	Output is correct
6	Correct	104 ms	17296 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	0 ms	344 KB	Output is correct
10	Correct	0 ms	348 KB	Output is correct
11	Correct	1 ms	344 KB	Output is correct
12	Correct	1 ms	344 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	Incorrect	1 ms	344 KB	Output isn't correct
17	Correct	0 ms	348 KB	Output is correct
18	Correct	1 ms	344 KB	Output is correct
19	Correct	1 ms	344 KB	Output is correct
20	Correct	0 ms	344 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	29 ms	13192 KB	Output isn't correct
24	Incorrect	35 ms	15184 KB	Output isn't correct
25	Correct	27 ms	9048 KB	Output is correct
26	Correct	24 ms	6884 KB	Output is correct
27	Correct	22 ms	6748 KB	Output is correct
28	Correct	24 ms	7088 KB	Output is correct
29	Correct	78 ms	14672 KB	Output is correct
30	Incorrect	36 ms	14668 KB	Output isn't correct
31	Incorrect	45 ms	19660 KB	Output isn't correct
32	Incorrect	32 ms	12232 KB	Output isn't correct
33	Correct	26 ms	9432 KB	Output is correct
34	Correct	24 ms	6772 KB	Output is correct
35	Correct	24 ms	6748 KB	Output is correct
36	Correct	28 ms	7104 KB	Output is correct
37	Correct	105 ms	17236 KB	Output is correct
38	Incorrect	40 ms	14960 KB	Output isn't correct
39	Incorrect	41 ms	11468 KB	Output isn't correct
40	Incorrect	33 ms	14536 KB	Output isn't correct
41	Correct	30 ms	9420 KB	Output is correct
42	Correct	24 ms	6556 KB	Output is correct
43	Correct	26 ms	6488 KB	Output is correct
44	Correct	28 ms	6988 KB	Output is correct
45	Correct	81 ms	14416 KB	Output is correct
46	Incorrect	36 ms	14420 KB	Output isn't correct
47	Incorrect	36 ms	14676 KB	Output isn't correct
48	Incorrect	41 ms	19292 KB	Output isn't correct
49	Correct	26 ms	9176 KB	Output is correct
50	Correct	23 ms	6748 KB	Output is correct
51	Correct	27 ms	6944 KB	Output is correct
52	Correct	24 ms	6736 KB	Output is correct
53	Correct	92 ms	14488 KB	Output is correct
54	Incorrect	35 ms	14164 KB	Output isn't correct