Submission #945959

#	Time	Username	Problem	Language	Result	Execution time	Memory
945959		efedmrlr	Power Plant (JOI20_power)	C++17	100 / 100	217 ms	29264 KiB

power

// #pragma GCC optimize("O3,Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>

using namespace std;


#define lli long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int i = 0; (i) < (n); (i)++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()


void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}


const double EPS = 0.00001;
const int INF = 1e9+500;
const int N = 3e5+5;
const int ALPH = 26;
const int LGN = 25;
constexpr int MOD = 1e9+7;
int n,m,q;
vector<vector<int> > adj;
vector<int> isPow;
vector<int> dp;
int ans = 0;
void dfs(int node, int par) {
    int sum = 0;
    for(auto c : adj[node]) {
        if(c == par) continue;
        dfs(c, node);
        sum += dp[c];
    }
    dp[node] = max(isPow[node], sum - isPow[node]);
    if(isPow[node]) {
        for(auto c : adj[node]) {
            ans = max(ans, dp[c] + 1);
        }
    }
}

inline void solve() {
    cin>>n;
    adj.assign(n + 1, vector<int>());
    isPow.assign(n + 1, 0);
    dp.assign(n + 1, 0);
    REP(i, n - 1) {
        int a,b;
        cin >> a >> b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    for(int i = 1; i <= n; i++) {
        char x;
        cin >> x;
        if(x == '1') isPow[i] = 1;
    }
    dfs(1, 0);
    ans = max(ans, dp[1]);
    cout << ans << "\n";
}
 
signed main() {

    //fastio();
    int test = 1;
    //cin>>test;
    while(test--) {
        solve();
    }
    
}

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