Submission #763067

#	Time	Username	Problem	Language	Result	Execution time	Memory
763067		huutuan	Power Plant (JOI20_power)	C++14	100 / 100	101 ms	25928 KiB

power

/*
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2,sse4.2,popcnt,lzcnt")
*/
 
#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define ll long long
#define ld long double
#define pb push_back
#define ff first
#define ss second
#define pii pair<int, int>
#define vi vector<int>
#define vii vector<pii>
using namespace std;
 
const int mxN = 2e5 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;
 
int n;
vi G[mxN];
bool vis[mxN];
int dp[mxN], ans;
 
void dfs(int v, int p) {
	int maxx = 0, cur_sum = 0;
	for(int u : G[v]) {
		if(u == p) continue;
		dfs(u, v);
		cur_sum += dp[u];
		maxx = max(maxx, dp[u]);
	}
	dp[v] = max(cur_sum - vis[v], (int)vis[v]);
	ans = max({ans, cur_sum - vis[v], maxx + vis[v]});
}
 
void solve() {
	cin >> n;
	for(int i = 1; i < n; ++i) {
		int u, v; cin >> u >> v;
		G[u].emplace_back(v);
		G[v].emplace_back(u);
	}
	for(int i = 1; i <= n; ++i) {
		char c; cin >> c;
		vis[i] = (c == '1');
	}
	dfs(1, 0);
	cout << ans << endl;
}
 
signed main() {
 
#ifndef CDuongg
    if(fopen(taskname".inp", "r"))
        assert(freopen(taskname".inp", "r", stdin)), assert(freopen(taskname".out", "w", stdout));
#else
    freopen("bai3.inp", "r", stdin);
    freopen("bai3.out", "w", stdout);
    auto start = chrono::high_resolution_clock::now();
#endif
 
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	int t = 1; //cin >> t;
	while(t--) solve();
 
#ifdef CDuongg
	auto end = chrono::high_resolution_clock::now();
	cout << "\n"; for(int i = 1; i <= 100; ++i) cout << '=';
	cout << "\nExecution time: " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
#endif
 
}

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