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Submission #1003590

# Submission time Handle Problem Language Result Execution time Memory
1003590 2024-06-20T13:26:30 Z aykhn Subtree (INOI20_subtree) C++17
12 / 100
 42 ms 24020 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
#define int long long
#define inf 0x3F3F3F3F3F3F3F3F
 
const int MXN = 1e5 + 5;
const int LOG = 20;
const int mod = 1e9 + 7;

vector<int> adj[MXN];
int p[MXN], used[MXN], down[MXN];
int in[MXN];
int dp[MXN];

void dfs(int a)
{
  dp[a] = 0;
  used[a] = 1;
  for (int &v : adj[a])
  {
    if (!used[v]) 
    {
      p[v] = a;
      dfs(v);
    }
    else if (v != p[a]) 
    {
      assert(!down[v]);
      down[v] = a;
    }
  }
  if (down[a])
  {
    vector<int> path;
    int x = down[a];
    while (x)
    {
      path.push_back(x);
      in[x] = 1;
      if (x == a) break;
      x = p[x];
    }
    reverse(path.begin(), path.end());
    vector<int> sum(path.size(), 0);
    int co = 1;
    for (int i = (int)path.size() - 1; i >= 0; i--)
    {
      if (i == (int)path.size() - 1) co = (co * dp[path[i]]) % mod;
      else
      {
        for (int &v : adj[path[i]]) 
        {
          if (!in[v] && v != p[path[i]]) co = (co * dp[v]) % mod;
        }
      }
      sum[i] = ((i + 1 < path.size() ? sum[i + 1] : 0) + co) % mod;
    }
    co = 1;
    for (int i = 0; i + 1 < path.size(); i++)
    {
      for (int &v : adj[path[i]])
      {
        if (!in[v] && v != p[path[i]]) 
        {
          co = (co * (dp[v] + 1)) % mod;
        }
      }
      dp[a] = (dp[a] + co) % mod;
      if (i + 2 < path.size()) dp[a] = (dp[a] + ((sum[i + 2] * co) % mod)) % mod;
    }
    for (int x : path) in[x] = 0;
  }
  else
  {
    dp[a] = 1;
    for (int &v : adj[a])
    {
      dp[a] = (dp[a] * (dp[v] + 1)) % mod;
    }
  }
}

signed main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  for (int i = 1; i <= m; i++)
  {
    int u, v;
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  dfs(1);
  int res = 0;
  for (int i = 1; i <= n; i++)
  {
    res = (res + dp[i]) % mod;
  }
  cout << res << '\n';
}

Compilation message

Main.cpp: In function 'void dfs(long long int)':
Main.cpp:58:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |       sum[i] = ((i + 1 < path.size() ? sum[i + 1] : 0) + co) % mod;
      |                  ~~~~~~^~~~~~~~~~~~~
Main.cpp:61:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |     for (int i = 0; i + 1 < path.size(); i++)
      |                     ~~~~~~^~~~~~~~~~~~~
Main.cpp:71:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |       if (i + 2 < path.size()) dp[a] = (dp[a] + ((sum[i + 2] * co) % mod)) % mod;
      |           ~~~~~~^~~~~~~~~~~~~

Subtask #1
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2648 KB Output is correct
2 Correct 1 ms 2648 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2648 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 2 ms 3016 KB Output is correct
8 Correct 1 ms 2652 KB Output is correct
9 Correct 1 ms 2652 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 1 ms 2816 KB Output is correct
13 Incorrect 1 ms 2808 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2652 KB Output is correct
2 Correct 3 ms 3420 KB Output is correct
3 Correct 29 ms 10012 KB Output is correct
4 Correct 27 ms 9820 KB Output is correct
5 Correct 28 ms 9820 KB Output is correct
6 Correct 27 ms 9808 KB Output is correct
7 Correct 42 ms 21080 KB Output is correct
8 Correct 34 ms 16980 KB Output is correct
9 Correct 32 ms 16988 KB Output is correct
10 Correct 26 ms 10576 KB Output is correct
11 Correct 23 ms 9860 KB Output is correct
12 Correct 36 ms 9308 KB Output is correct
13 Correct 30 ms 9560 KB Output is correct
14 Correct 27 ms 14536 KB Output is correct
15 Correct 35 ms 22356 KB Output is correct
16 Correct 36 ms 24020 KB Output is correct
17 Correct 28 ms 9296 KB Output is correct
18 Correct 29 ms 9548 KB Output is correct
19 Correct 38 ms 9300 KB Output is correct
20 Correct 21 ms 9924 KB Output is correct
21 Correct 23 ms 10068 KB Output is correct
22 Correct 23 ms 10072 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2648 KB Output is correct
2 Correct 1 ms 2648 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2648 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 2 ms 3016 KB Output is correct
8 Correct 1 ms 2652 KB Output is correct
9 Correct 1 ms 2652 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 1 ms 2816 KB Output is correct
13 Incorrect 1 ms 2808 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2648 KB Output is correct
2 Correct 1 ms 2648 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2648 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 2 ms 3016 KB Output is correct
8 Correct 1 ms 2652 KB Output is correct
9 Correct 1 ms 2652 KB Output is correct
10 Correct 1 ms 2648 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 1 ms 2816 KB Output is correct
13 Incorrect 1 ms 2808 KB Output isn't correct
14 Halted 0 ms 0 KB -