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Submission #1003094

# Submission time Handle Problem Language Result Execution time Memory
1003094 2024-06-20T06:01:49 Z vjudge1 Subtree (INOI20_subtree) C++17
12 / 100
 39 ms 23896 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 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2812 KB Output is correct
4 Correct 1 ms 2812 KB Output is correct
5 Correct 1 ms 2816 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2652 KB Output is correct
8 Correct 2 ms 2908 KB Output is correct
9 Correct 1 ms 2648 KB Output is correct
10 Correct 2 ms 2652 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 1 ms 2652 KB Output is correct
13 Incorrect 1 ms 2652 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 1 ms 2648 KB Output is correct
2 Correct 3 ms 3420 KB Output is correct
3 Correct 27 ms 9868 KB Output is correct
4 Correct 28 ms 9808 KB Output is correct
5 Correct 27 ms 9820 KB Output is correct
6 Correct 35 ms 10132 KB Output is correct
7 Correct 38 ms 20820 KB Output is correct
8 Correct 39 ms 17064 KB Output is correct
9 Correct 35 ms 16976 KB Output is correct
10 Correct 23 ms 10588 KB Output is correct
11 Correct 23 ms 9784 KB Output is correct
12 Correct 29 ms 9308 KB Output is correct
13 Correct 27 ms 9500 KB Output is correct
14 Correct 26 ms 14544 KB Output is correct
15 Correct 35 ms 22500 KB Output is correct
16 Correct 36 ms 23896 KB Output is correct
17 Correct 29 ms 9308 KB Output is correct
18 Correct 31 ms 9556 KB Output is correct
19 Correct 28 ms 9564 KB Output is correct
20 Correct 24 ms 9936 KB Output is correct
21 Correct 23 ms 10344 KB Output is correct
22 Correct 23 ms 10076 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2812 KB Output is correct
4 Correct 1 ms 2812 KB Output is correct
5 Correct 1 ms 2816 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2652 KB Output is correct
8 Correct 2 ms 2908 KB Output is correct
9 Correct 1 ms 2648 KB Output is correct
10 Correct 2 ms 2652 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 1 ms 2652 KB Output is correct
13 Incorrect 1 ms 2652 KB Output isn't correct
14 Halted 0 ms 0 KB -

Subtask #4
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2812 KB Output is correct
4 Correct 1 ms 2812 KB Output is correct
5 Correct 1 ms 2816 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2652 KB Output is correct
8 Correct 2 ms 2908 KB Output is correct
9 Correct 1 ms 2648 KB Output is correct
10 Correct 2 ms 2652 KB Output is correct
11 Correct 1 ms 2652 KB Output is correct
12 Correct 1 ms 2652 KB Output is correct
13 Incorrect 1 ms 2652 KB Output isn't correct
14 Halted 0 ms 0 KB -