제출 #855790

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
855790		mychecksedad	Mousetrap (CEOI17_mousetrap)	C++17	0 / 100	198 ms	69940 KiB

mousetrap

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
const int N = 1e6+100, M = 1e5+10, K = 22;

int n, s, t, dp[N];
vector<int> g[N];
void dfs(int v, int p){
  dp[v] = 0;
  vector<int> dps;
  for(int u: g[v]){
    if(u != p && u != t){
      dfs(u, v);
      dps.pb(dp[u] + 1);
    }
  }
  sort(all(dps), greater<int>());
  dp[v] = dps.size() <= 1 ? 0 : dps[1];
}

void solve(){
  cin >> n >> s >> t;
  for(int i = 0; i < n - 1; ++i){
    int u, v; cin >> u >> v;
    g[u].pb(v);
    g[v].pb(u);
  }
  dfs(s, 0);
  cout << dp[s] * 3;
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

컴파일 시 표준 에러 (stderr) 메시지

mousetrap.cpp: In function 'int main()':
mousetrap.cpp:41:15: warning: unused variable 'aa' [-Wunused-variable]
   41 |   int tt = 1, aa;
      |               ^~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 20
• Subtask 4: 0 / 35