제출 #1165309

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1165309		MPG	Power Plant (JOI20_power)	C++20	100 / 100	74 ms	36796 KiB

power

//#pragma GCC optomize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse4.1,sse4.2") 



#include <bits/stdc++.h>
using namespace std;
typedef long long                           ll;
#define                                     max_heap priority_queue<pair <ll, pair <ll, ll>>>
#define                                     min_heap priority_queue<pair <ll, ll>, vector<pair <ll, ll>>, greater<pair <ll, ll>>>
//#define                                     min_heap priority_queue<ll, vector<ll>, greater<ll>>
#define                                     sariE cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define                                     filE freopen("in.txt", "r", stdin); freopen("out1.txt", "w", stdout); 
#define                                     endl '\n'
#define                                     md(a) (a % mod + mod) % mod
#define pb push_back
//cout << vectorprecision(5) << fixed << f;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll const maxn = 2e5 + 123;
ll const inf = 2e12;
ll const loG = 23;
ll const mod = 1e9 + 7;
//ll const mod = 998244353;
ll const sq = 350;
ll power(ll a, ll b, ll mod){if(b==0)return 1;if(b==1)return a;ll x = power(a, b / 2, mod);return (((x * x) % mod) * (b % 2 ? a : 1)) % mod;}



ll n, dp[maxn][2], col[maxn];
vector <ll> g[maxn];


void dfs(ll v, ll p){
    ll mx0 = 0, mx1 = 0, sum0 = 0, sum1 = 0;
    for (ll u : g[v]){
        if (u != p){
            dfs(u, v);
            mx0 = max(mx0, dp[u][0]);
            mx1 = max(mx1, dp[u][1]);
            sum0 += max((ll)0, dp[u][0]);
            sum1 += max((ll)0, dp[u][1]);
        }
    }
    //cout << v << ' ' << col[v]  << ' ' << sum0 << ' ' << mx1 << endl;
    if (col[v]){
        dp[v][0] = max(max(mx1 + 1, mx0), max((ll)1, sum1 - 1));
        //dp[v][0] = max({(ll)1, sum0 - 1, mx1 + 1});
        dp[v][1] = max((ll)1, sum1 - 1);
    }
    else{
        dp[v][0] = max(sum1, mx0);
        dp[v][1] = sum1;
    }
}

string s;

void Solve(){

cin >> n;
for (int i = 1; i < n; i++){
    ll a, b; cin >> a >> b;
    g[a].push_back(b);
    g[b].push_back(a);
}
cin >> s;
s = ' ' + s;
for (int i = 1; i < n + 1; i++){
    if (s[i] == '1')
        col[i] = 1;
}
dfs(1, 1);
// for (int i = 1; i < n + 1; i++){
//     cout << i << ' ' << col[i] << ' ' << dp[i][0] << ' ' << dp[i][1] << endl;
// }
cout << dp[1][0] << endl;


}



int main(){
sariE;// filE;



int test = 1;
//cin >> test;
while (test--) Solve();
return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53