Submission #369422

#	Time	Username	Problem	Language	Result	Execution time	Memory
369422		jhnah917	Power Plant (JOI20_power)	C++14	100 / 100	196 ms	26988 KiB

power

/******************************
Author: jhnah917(Justice_Hui)
g++ -std=c++17 -DLOCAL
******************************/

#include <bits/stdc++.h>
#define x first
#define y second
#define all(v) v.begin(), v.end()
#define compress(v) sort(all(v)), v.erase(unique(all(v)), v.end())
#define IDX(v, x) lower_bound(all(v), x) - v.begin()
using namespace std;

using uint = unsigned;
using ll = long long;
using ull = unsigned long long;

int N, R;
bool S[202020];
vector<int> G[202020];

int DFS(int v, int b){
    int t1 = 0, t2 = S[v];
    for(const auto &i : G[v]){
        if(i == b) continue;
        int t = DFS(i, v);
        t1 += t; t2 = max(t2, t + S[v]);
    }
    t1 = max<int>(S[v], t1 - S[v]);
    R = max({R, t1, t2});
    return t1;
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(nullptr);
    cin >> N;
    for(int i=1; i<N; i++){
        int s, e; cin >> s >> e;
        G[s].push_back(e); G[e].push_back(s);
    }
    for(int i=1; i<=N; i++){ char c; cin >> c; S[i] = c == '1'; }
    DFS(1, -1);
    cout << R;
}

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