Submission #3834001

---

Source Code Expand

#include <iostream>
#include <stdio.h>
#include <fstream>
#include <algorithm>
#include <string>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <limits.h>
#include <math.h>
#include <functional>
#include <bitset>
#include <iomanip>
#include <cassert>

#define repeat(i,n) for (long long i = 0; (i) < (n); ++ (i))
#define debug(x) cerr << #x << ": " << x << '\n'
#define debugArray(x,n) for(long long i = 0; (i) < (n); ++ (i)) cerr << #x << "[" << i << "]: " << x[i] << '\n'
#define debugArrayP(x,n) for(long long i = 0; (i) < (n); ++ (i)) cerr << #x << "[" << i << "]: " << x[i].first<< " " << x[i].second << '\n'

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> Pii;
typedef vector<int> vint;
typedef vector<ll> vll;
const ll INF = INT_MAX;
const ll MOD = 1e9+7;

int N,K;
vector<vint> G;
ll dp[112345][2];
ll size[112345];
ll cnt[112345];

void dfs(int v,int par){
  size[v]=1;
  for(int chi:G[v])if(chi!=par){
    dfs(chi,v);
    size[v] += size[chi];
    cnt[v] += size[chi]>=K;
  }
  for(int chi:G[v])if(chi!=par){
    dp[v][0] = max(dp[v][0],dp[chi][0]);
    if(size[chi]>1)dp[v][0] = max(dp[v][0],dp[chi][1]+(N-size[chi]>=K));
    if(size[chi]>1)dp[v][0] = max(dp[v][0],dp[chi][1]+dp[v][1]-(size[chi]>=K)+(N-size[v]>=K));
    dp[v][0] = max(dp[v][0],cnt[chi]+dp[v][1]-(size[chi]>=K)+(N-size[v]>=K));
    if(size[chi]>1)dp[v][1] = max(dp[v][1],dp[chi][1]+cnt[v]-(size[chi]>=K));
    dp[v][1] = max(dp[v][1],cnt[chi]+cnt[v]-(size[chi]>=K));
  }
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >>N>>K;
  G.resize(N);
  repeat(i,N-1){
    int u,v;cin>>u>>v;u--;v--;
    G[u].push_back(v);
    G[v].push_back(u);
  }
  dfs(0,-1);
  cout << max(dp[0][0],dp[0][1]) << endl;
  return 0;
}

Submission Info

Judge Result