답안 #424292

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
424292 2021-06-11T19:21:49 Z abdzag Power Plant (JOI20_power) C++17
0 / 100
84 ms 86368 KB
#include<bits/stdc++.h>
#include<unordered_map>
#define rep(i,a,b) for(int i=int(a);i<int(b);i++)
#define rrep(i,a,b) for(int i=int(a);i>int(b);i--)
#define trav(a,v) for(auto& a: v)
#define sz(v) v.size()
#define all(v) v.begin(),v.end()
#define vi vector<int>

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
const long long inf = 1e15;

using namespace std;
vector<vector<ll>> dp(1e6,vector<ll>(2,-inf));
vector<ll> parents(1e6);
vector<vector<ll>> children(1e6);
string s;
ll solve(ll cur,bool lit) {
	if (children[cur].size() == 0) {
		return s[cur-1] == '1';
	}
	if (dp[cur][lit] != -inf)return dp[cur][lit];
	ll ans1=-inf;
	ll ans2=-inf;
	ll ans3 = 0;
	ll ans4 = 0;
	trav(a, children[cur]) {
		ans1 = max(ans1, solve(a,lit));
	}
	trav(a, children[cur]) {
		ans2 = max(ans2, solve(a, 1));
	}
	ll one = 1;
	ll zero = 0;
	if (s[cur - 1] == '1') {
		if(lit)ans2 -= 1, ans1 -= 1;
	}
	ans1 = max(zero, ans1);
	ans2 = max(one, ans2);
	trav(a, children[cur]) {
		ans3 += solve(a, 1);
	}
	trav(a, children[cur]) {
		ans4 += solve(a, lit);
	}
	if (s[cur - 1] == '1') {
		ans3--;
		ans4--;
	}
	return dp[cur][lit] = max(max(ans1, ans2),max(ans3,ans4));
}
int main() {
	cin.sync_with_stdio(false);
	ll n;
	cin >> n;
	vector<vector<ll>> g(n + 1);
	rep(i, 0, n-1) {
		ll a, b;
		cin >> a >> b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	cin >> s;
	if (n == 1) {
		cout << (s == "1" ? 1 : 0)<<endl;
	}
	else if (n == 2) {
		ll ans = 0;
		trav(a, s)ans += a == '1';
		cout << ans << endl;
	}
	queue<ll> q;
	vector<bool> isLeaf(n+1);
	rep(i, 1, n + 1)if (g[i].size() == 1)isLeaf[i]=1;
	ll root = -1;
	rep(i, 1, n + 1)if (!isLeaf[i])root = i;
	q.push(root);
	vector<bool> visited(n + 1);
	visited[root] = 1;
	while (!q.empty()) {
		ll cur = q.front();
		q.pop();
		trav(a, g[cur]) {
			if (!visited[a]) {
				parents[a] = cur;
				children[cur].push_back(a);
				visited[a] = 1;
				q.push(a);
			}
		}
	}
	rep(i, 1, n + 1) {
		if (isLeaf[i]) {
			q.push(i);
		}
	}
	parents[root] = -1;
	cout << solve(root,0);
	return 0;
}
# 결과 실행 시간 메모리 Grader output
1 Incorrect 84 ms 86368 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Incorrect 84 ms 86368 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Incorrect 84 ms 86368 KB Output isn't correct
2 Halted 0 ms 0 KB -