Submission #626746

#	Time	Username	Problem	Language	Result	Execution time	Memory
626746		MilosMilutinovic	Burza (COCI16_burza)	C++14	0 / 160	895 ms	3540 KiB

burza

/**
 *    author:  wxhtzdy
 *    created: 11.08.2022 19:27:55
**/
#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);  
  int n, k;
  cin >> n >> k;
  vector<vector<int>> g(n);
  for (int i = 0; i < n - 1; i++) {
    int u, v;
    cin >> u >> v;
    --u; --v;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  if (k > 21) {
    cout << "DA" << '\n';
    return 0;
  }                          
  vector<int> dep(n);
  vector<int> dfn(n);
  vector<int> dfo(n);
  int T = 0;
  vector<vector<int>> par(n);
  function<void(int, int)> Dfs = [&](int v, int pr) {
    dfn[v] = ++T;
    for (int p : par[pr]) {
      par[v].push_back(p);
    }
    par[v].push_back(v);
    for (int u : g[v]) {
      if(u == pr) {
        continue;
      }
      dep[u] = dep[v] + 1;
      Dfs(u, v);
    }
    dfo[v] = T;
  };
  Dfs(0, 0);
  vector<vector<int>> at(n);
  for (int i = 0; i < n; i++) {
    at[dep[i]].push_back(i);
  }
  for (int i = 0; i < n; i++) {
    sort(at[i].begin(), at[i].end(), [&](int i, int j) {
      return dfn[i] < dfn[j];
    });
  }
  auto isPar = [&](int v, int u) {
    return dfn[v] <= dfn[u] && dfo[u] <= dfo[v];
  };
  vector<int> ptr(n);
  int sz = (int) at[k].size();
  for (int i = 1; i < n; i++) {
    if (dep[i] > k) {
      continue;      
    }
    int low = 0, high = sz - 1;
    while (low <= high) {
      int mid = low + high >> 1;
      if (isPar(i, at[k][mid])) {
        ptr[i] = mid;
        low = mid + 1;
      } else {
        if (dfn[i] < at[k][mid]) {
          high = mid - 1;
        } else {
          low = mid + 1;
        }
      }
    }
  }                           
  vector<vector<bool>> dp(sz + 1, vector<bool>(1 << (k + 1)));
  dp[0][0] = true;
  for (int i = 0; i < sz; i++) {
    int v = at[k][i];
    for (int s = 0; s < (1 << (k + 1)); s++) {
      for (int idx : par[v]) {
        if (idx == 0) {
          continue;
        }
        if (s >> dep[idx] & 1) {
          continue;
        } 
        if (dp[i][s]) {
          dp[ptr[idx] + 1][s | (1 << dep[idx])] = true;
        }
      }    
    }
  }
  bool ans = false;
  for (int i = 0; i < (1 << (k + 1)); i++) {
    ans = (ans | dp[sz][i]);
  }
  cout << (ans ? "DA" : "NE") << '\n'; 
  return 0;
}

Compilation message (stderr)

burza.cpp: In function 'int main()':
burza.cpp:67:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   67 |       int mid = low + high >> 1;
      |                 ~~~~^~~~~~

• Subtask 1: 0 / 16
• Subtask 2: 0 / 16
• Subtask 3: 0 / 16
• Subtask 4: 0 / 16
• Subtask 5: 0 / 16
• Subtask 6: 0 / 16
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• Subtask 10: 0 / 16