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Submission #1003103

# Submission time Handle Problem Language Result Execution time Memory
1003103 2024-06-20T06:10:52 Z vjudge1 Subtree (INOI20_subtree) C++17
12 / 100
 38 ms 24668 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], t[MXN], tim;
int dp[MXN];

void dfs(int a)
{
  t[a] = ++tim;
  dp[a] = 0;
  used[a] = 1;
  for (int &v : adj[a])
  {
    if (!used[v]) 
    {
      p[v] = a;
      dfs(v);
    }
    else if (v != p[a] && t[v] < t[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;
      else assert(!down[x]);
      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] + 1)) % 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:60:24: 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]
   60 |       sum[i] = ((i + 1 < path.size() ? sum[i + 1] : 0) + co) % mod;
      |                  ~~~~~~^~~~~~~~~~~~~
Main.cpp:63:27: 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]
   63 |     for (int i = 0; i + 1 < path.size(); i++)
      |                     ~~~~~~^~~~~~~~~~~~~
Main.cpp:73:17: 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]
   73 |       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 2652 KB Output is correct
2 Correct 2 ms 2652 KB Output is correct
3 Correct 1 ms 2840 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2652 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 2652 KB Output is correct
11 Correct 1 ms 2812 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 2652 KB Output is correct
2 Correct 3 ms 3420 KB Output is correct
3 Correct 31 ms 10644 KB Output is correct
4 Correct 31 ms 10584 KB Output is correct
5 Correct 28 ms 10840 KB Output is correct
6 Correct 31 ms 10580 KB Output is correct
7 Correct 35 ms 21700 KB Output is correct
8 Correct 34 ms 17612 KB Output is correct
9 Correct 33 ms 17744 KB Output is correct
10 Correct 24 ms 11356 KB Output is correct
11 Correct 28 ms 10636 KB Output is correct
12 Correct 31 ms 10072 KB Output is correct
13 Correct 28 ms 10068 KB Output is correct
14 Correct 25 ms 15304 KB Output is correct
15 Correct 34 ms 23124 KB Output is correct
16 Correct 38 ms 24668 KB Output is correct
17 Correct 28 ms 10064 KB Output is correct
18 Correct 29 ms 10324 KB Output is correct
19 Correct 30 ms 10184 KB Output is correct
20 Correct 22 ms 10956 KB Output is correct
21 Correct 29 ms 11100 KB Output is correct
22 Correct 25 ms 10844 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2652 KB Output is correct
2 Correct 2 ms 2652 KB Output is correct
3 Correct 1 ms 2840 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2652 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 2652 KB Output is correct
11 Correct 1 ms 2812 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 2652 KB Output is correct
2 Correct 2 ms 2652 KB Output is correct
3 Correct 1 ms 2840 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 1 ms 2652 KB Output is correct
7 Correct 1 ms 2652 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 2652 KB Output is correct
11 Correct 1 ms 2812 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 -