제출 #133439

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
133439		tdwn	Mag (COCI16_mag)	C++17	48 / 120	1734 ms	140396 KiB

mag

#include <bits/stdc++.h>
#define ll long long 
#define pb push_back
#define mp make_pair
using namespace std;
const int maxn = 1000100;
vector<int>g[maxn];
ll arr[maxn], n;
ll dp[maxn], result1;
ll result2;
 
ll dpup[maxn];
 
void dfs(int node, int p) {
	vector<ll>v;
 
	if(p != -1) {
		if(arr[node] == 1) dpup[node] = 1 + dpup[p];
		else dpup[node] = 0;
	}
 	else if(arr[node] == 1) dpup[node] = 1;

	for(int i:g[node]) {
		if(i != p) {
			dfs(i, node);
 
			if(arr[i] == 1) {
				v.pb(dp[i]);
			}
		}
	}

 
	if(arr[node] == 2) {
		if(p == -1) v.pb(0);
		else v.pb(dpup[p]);
		v.pb(0);
		sort(v.rbegin(), v.rend());
 
		//cout<<node<<": "<<v[0]<<" "<<v[1]<<"\n";
 
		result2 = max(result2, v[0] + v[1] + 1LL);
		return;
	}
 
	if(arr[node] != 1) return;
	sort(v.rbegin(), v.rend());
 
	if(v.size() == 0) {
		dp[node] = 1LL;
		result1 = max(result1, dp[node]);
	}
 
	if(v.size() == 1) {
		dp[node] = 1 + v[0];
		result1 = max(result1, dp[node]);
	}
	else if(v.size() > 1){
		dp[node] = 1 + v[0];
		result1 = max(result1, v[0] + v[1] + 1);
	}
}
 
int main() {
	cin>>n;
	ll a, b;
	for(int i=0;i<n-1;i++) {
		cin>>a>>b;
		g[a].pb(b);
		g[b].pb(a);
	}
 
	ll minval = LLONG_MAX;
	for(int i=1;i<=n;i++) {
		cin>>arr[i];
		minval = min(minval, arr[i]);
	}
 
	if(minval != 1) {
		cout<<minval<<"/1\n";
	}
	else {
		dfs(400001, -1);
		if(result2 > 2*result1) {
			cout<<"2/"<<result2<<"\n";
		}
		else {
			cout<<"1/"<<result1<<"\n";
		}
	}
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 12
• Subtask 3: 0 / 12
• Subtask 4: 0 / 12
• Subtask 5: 12 / 12
• Subtask 6: 12 / 12
• Subtask 7: 0 / 12
• Subtask 8: 0 / 12
• Subtask 9: 12 / 12
• Subtask 10: 12 / 12