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Submission #1108784

# Submission time Handle Problem Language Result Execution time Memory
1108784 2024-11-05T04:57:44 Z TrungDuy3107 Bi-ing Lottery Treekets (CCO22_day2problem1) C++14
4 / 25
 47 ms 126288 KB 
#include<bits/stdc++.h>
using namespace std;

#define maxn 4'007
#define MOD 1'000'000'007
#define int long long
typedef long long LL;
int fact[maxn], invF[maxn];
int power(int a, int n)
{
  int res = 1;
  for(;n;n>>=1,a=1LL*a*a%MOD)
    if(n&1) res = 1LL*res*a%MOD;
  return res;
}
int n;
vector<int> g[maxn];
int cnt[maxn];
int dp[maxn][maxn];
int len[maxn];
int tmp[maxn];

void dfs(int u)
{
  len[u] = 1;
  if(g[u].size() == 0) dp[u][0] = 1;
  if(g[u].size() == 1) {
    dfs(g[u][0]);
    for(int i=0;i<=len[g[u][0]];i++) dp[u][i] = dp[g[u][0]][i];
    len[u] += len[g[u][0]];
  }
  if(g[u].size() == 2) {
    int a = g[u][0], b = g[u][1];
    dfs(a);dfs(b);
    for(int i=0;i<=len[a];i++)
      for(int j=0;j<=len[b];j++) {
        dp[u][i+j] += 1LL*dp[a][i]*dp[b][j]%MOD;
        if(dp[u][i+j] >= MOD) dp[u][i+j] -= MOD;
      }
    len[u] += len[a]+len[b];
  }
  dp[u][len[u]] = dp[u][len[u]-1];
  for(int i=0;i<=len[u]-cnt[u];i++) {
    dp[u][i] = (1LL*dp[u][i+cnt[u]]*fact[i+cnt[u]]%MOD)*invF[i]%MOD;
  }
  if(cnt[u] > len[u]) {
    for(int i=0;i<=len[u];i++) dp[u][i] = 0;
  }
  len[u] = max(len[u]-cnt[u],0LL);
//  cout << u << '\n';
//  for(int i=0;i<=len[u];i++) cout << dp[u][i] << ' ';cout << '\n';
}
int32_t main()
{
  ios::sync_with_stdio(0);
  cin.tie(0);cout.tie(0);

  int k;
  cin >> n >> k;
  fact[0] = 1;
  for(int i=1;i<=n;i++) fact[i] = 1LL*fact[i-1]*i%MOD;
  invF[n] = power(fact[n], MOD-2);
  for(int i=n-1;i>=0;i--) invF[i] = 1LL*invF[i+1]*(i+1)%MOD;
  for(int i=1;i<=k;i++) {
    int input;
    cin >> input;
    cnt[input]++;
  }
  for(int i=1;i<=n;i++) {
    int u, v;
    cin >> u >> v;
    if(u) g[i].push_back(u);
    if(v) g[i].push_back(v);
  }
  dfs(1);
  cout << dp[1][0];
  return 0;
}

Subtask #1
0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 1 ms 2640 KB Output is correct
5 Correct 2 ms 2384 KB Output is correct
6 Incorrect 1 ms 2640 KB Output isn't correct
7 Halted 0 ms 0 KB -

Subtask #2
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 126288 KB Output is correct
2 Correct 29 ms 126288 KB Output is correct
3 Correct 8 ms 68432 KB Output is correct
4 Correct 15 ms 126288 KB Output is correct
5 Correct 14 ms 126288 KB Output is correct
6 Correct 12 ms 126228 KB Output is correct
7 Correct 22 ms 126288 KB Output is correct
8 Correct 15 ms 126288 KB Output is correct
9 Correct 18 ms 126288 KB Output is correct
10 Correct 47 ms 126288 KB Output is correct
11 Correct 36 ms 126232 KB Output is correct
12 Correct 7 ms 60256 KB Output is correct
13 Correct 39 ms 118096 KB Output is correct
14 Correct 28 ms 115792 KB Output is correct
15 Correct 13 ms 111696 KB Output is correct
16 Correct 45 ms 122192 KB Output is correct
17 Correct 36 ms 113756 KB Output is correct

Subtask #3
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 75856 KB Output is correct
2 Correct 14 ms 126204 KB Output is correct
3 Correct 14 ms 88400 KB Output is correct
4 Incorrect 16 ms 99324 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #4
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 1 ms 2640 KB Output is correct
5 Correct 2 ms 2384 KB Output is correct
6 Incorrect 1 ms 2640 KB Output isn't correct
7 Halted 0 ms 0 KB -