Submission #867643

#	Time	Username	Problem	Language	Result	Execution time	Memory
867643		Cookie	Cat in a tree (BOI17_catinatree)	C++14	0 / 100	2 ms	8536 KiB

catinatree

#include<bits/stdc++.h>
#include<fstream>
using namespace std;
ifstream fin("paint.inp");
ofstream fout("paint.out");
#define sz(a) (int)a.size()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const ld PI = 3.14159265359;
using u128 = __uint128_t;
const int x[4] = {1, -1, 0, 0};
const int y[4] = {0, 0, 1, -1};
const ll mod = 1e9 + 7, inf = 1e9;
const int mxn = 3e5 + 5;
int n, d;
pll dp[mxn + 1];
vt<int>adj[mxn + 1];
int dep[mxn + 1];
void dfs(int s, int pre){
    vt<pll>comp;
    for(auto i: adj[s]){
        if(i != pre){
            dep[i] = dep[s] + 1;
            dfs(i, s);
            comp.pb(dp[i]);
        }
    }
    // dp[i] = [max depth, max taken]
    sort(comp.rbegin(), comp.rend());
    ll mndep = inf;
    for(auto [de, tak]: comp){
        if(de + mndep - 2 * dep[s] >= d){
            dp[s].second += tak; mndep = min(mndep, de);
        }else{
            dp[s].second += tak - 1;
        }
    }
    if(mndep - dep[s] >= d){
        dp[s].second++; mndep = dep[s];
    }
    dp[s].first = mndep;
}
signed main()
{
     ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
   cin >> n >> d;
   for(int i = 1; i < n; i++){
       int u, v; cin >> u >> v;
       adj[u].pb(v); adj[v].pb(u);
   }
   dfs(1, -1);
   cout << dp[1].second;
    return(0);
}

Compilation message (stderr)

catinatree.cpp: In function 'void dfs(int, int)':
catinatree.cpp:40:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   40 |     for(auto [de, tak]: comp){
      |              ^

• Subtask 1: 0 / 11
• Subtask 2: 0 / 40
• Subtask 3: 0 / 49