oj.uz

Submission #1003099

# Submission time Handle Problem Language Result Execution time Memory
1003099 2024-06-20T06:06:25 Z vjudge1 Subtree (INOI20_subtree) C++17
12 / 100
 37 ms 23804 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;
      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:59:24: 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]
   59 |       sum[i] = ((i + 1 < path.size() ? sum[i + 1] : 0) + co) % mod;
      |                  ~~~~~~^~~~~~~~~~~~~
Main.cpp:62:27: 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]
   62 |     for (int i = 0; i + 1 < path.size(); i++)
      |                     ~~~~~~^~~~~~~~~~~~~
Main.cpp:72:17: 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]
   72 |       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 Runtime error 3 ms 5212 KB Execution killed with signal 6
2 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 5 ms 3420 KB Output is correct
3 Correct 26 ms 10060 KB Output is correct
4 Correct 37 ms 9808 KB Output is correct
5 Correct 32 ms 10000 KB Output is correct
6 Correct 27 ms 9820 KB Output is correct
7 Correct 35 ms 20848 KB Output is correct
8 Correct 32 ms 16980 KB Output is correct
9 Correct 31 ms 16976 KB Output is correct
10 Correct 23 ms 10840 KB Output is correct
11 Correct 22 ms 9904 KB Output is correct
12 Correct 27 ms 9448 KB Output is correct
13 Correct 32 ms 9300 KB Output is correct
14 Correct 28 ms 14532 KB Output is correct
15 Correct 34 ms 22356 KB Output is correct
16 Correct 37 ms 23804 KB Output is correct
17 Correct 28 ms 9308 KB Output is correct
18 Correct 35 ms 9552 KB Output is correct
19 Correct 31 ms 9552 KB Output is correct
20 Correct 21 ms 9924 KB Output is correct
21 Correct 21 ms 10332 KB Output is correct
22 Correct 25 ms 10068 KB Output is correct

Subtask #3
0 / 30.0

# Verdict Execution time Memory Grader output
1 Runtime error 3 ms 5212 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #4
0 / 50.0

# Verdict Execution time Memory Grader output
1 Runtime error 3 ms 5212 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -