oj.uz

답안 #766051

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
766051 2023-06-25T09:28:23 Z yusuf12360 Power Plant (JOI20_power) C++14
0 / 100
 1 ms 212 KB 
#include<bits/stdc++.h>
using namespace std;
int ans=1;
vector<int> res;
vector<vector<int>> adj;
string s;
void dfs1(int u=0, int p=-1) {
	res[u]=s[u]-'0';
	for(int pp : adj[u]) {
		if(pp==p) continue;
		dfs1(pp, u);
		if(s[pp]=='1') res[u]++;
		else res[u]+=res[pp];
	}
}
void dfs2(int u=0, int p=-1, int to_p=0) {
	int sz=adj[u].size();
	if(p!=-1 || s[u]=='0') ans=max(ans, res[u]+to_p-2*(s[u]=='1')*(sz>1));
	else {
		int cnt=0, mn=2;
		for(int pp : adj[0]) {if(res[pp]>0) cnt++, mn=min(mn, res[pp]);}
		if(cnt==1) ans=max(ans, res[0]);
		else ans=max(ans, res[0]-mn);
	}
	if(u && s[u]=='1') {
		int cnt=0, mn=2, jalur;
		if(to_p>0) cnt++, mn=min(mn, to_p), jalur=to_p;
		for(int pp : adj[u]) {if(res[pp]>0) cnt++, mn=min(mn, res[pp]), jalur=res[pp];}
		if(cnt==1) ans=max(ans, jalur+1);
		else ans=max(ans, res[u]+to_p-mn);
	}
	for(int pp : adj[u]) {
		if(pp==p) continue;
		if(s[u]=='1') dfs2(pp, u, 1);
		else dfs2(pp, u, to_p+res[u]-(s[pp]=='1' ? 1 : res[pp]));
	}
}
int main() {
	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	int n; cin >> n;
	res.resize(n); adj.resize(n);
	while(--n) {
		int u, v; cin >> u >> v; --u; --v;
		adj[u].push_back(v);
		adj[v].push_back(u);}
	cin >> s;
	dfs1();
	dfs2();
	cout << ans << '\n';
	return 0;
}

Subtask #1
0.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Incorrect 1 ms 212 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #2
0.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Incorrect 1 ms 212 KB Output isn't correct
6 Halted 0 ms 0 KB -

Subtask #3
0.0 / 53.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Incorrect 1 ms 212 KB Output isn't correct
6 Halted 0 ms 0 KB -