Submission #275951

#	Time	Username	Problem	Language	Result	Execution time	Memory
275951		theStaticMind	Dynamic Diameter (CEOI19_diameter)	C++14	36 / 100	5051 ms	35152 KiB

diameter

#include<bits/stdc++.h>
#define pb push_back
#define ii pair<int,int>
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define INF 100000000000000000
#define modulo 1000000007
#define mod 998244353
#define int long long int
using namespace std;
int n;

vector<ii> adj[100005];
vector<ii> edge;
int anc[20][100005];
int depth[100005];

multiset<int> diameter;
multiset<int> data[100005];
map<int, int> ptr;

int getedge(int x, int y){
	return lower_bound(all(adj[x]), ii{y, -1}) - adj[x].begin();
}

int getdia(int x){
	if(data[x].empty()) return 0;
	if(data[x].size() == 1) return *data[x].rbegin();
	return *data[x].rbegin() + *++data[x].rbegin();
}
int getmax(int x){
	if(data[x].empty()) return 0;
	return *data[x].rbegin();	
}

void update(int x, int y){
	diameter.erase(diameter.find(getdia(x)));
	data[x].erase(data[x].lower_bound(ptr[y]));
	ptr[y] = getmax(y) + adj[x][getedge(x, y)].second;
	data[x].insert(ptr[y]);
	diameter.insert(getdia(x));
}

void init(int x, int pre){

	for(auto p : adj[x]){
		int y = p.first;
		if(y == pre) continue;
		
		anc[0][y] = x;
		depth[y] = depth[x] + 1;

		init(y, x);

		data[x].insert(getmax(y) + p.second);
		ptr[y] = getmax(y) + p.second;

	}

	diameter.insert(getdia(x));
}


int32_t main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	int q, W;
	cin >> n >> q >> W;

	for(int i = 0; i < n - 1; i++){
		int x, y, z;
		cin >> x >> y >> z;
		adj[x].pb({y, z});
		adj[y].pb({x, z});

		edge.pb({x, y});
	}

	for(int i = 1; i <= n; i++){
		sort(all(adj[i]));
	}

	init(1, 0);

	int last = 0;

	while(q--){
		ii p;
		cin >> p.first >> p.second;
		p.first = (p.first + last) % (n - 1);
		p.second = (p.second + last) % W;
		int x = edge[p.first].first;
		int y = edge[p.first].second;
		int z = p.second;

		adj[x][getedge(x, y)].second = z;
		adj[y][getedge(y, x)].second = z;

		if(depth[x] > depth[y]) swap(x, y);

		while(x){
			update(x, y);
			y = x;
			x = anc[0][x];
		}

		last = *diameter.rbegin();
		cout << last << "\n";
	}
}

• Subtask 1: 11 / 11
• Subtask 2: 0 / 13
• Subtask 3: 7 / 7
• Subtask 4: 18 / 18
• Subtask 5: 0 / 24
• Subtask 6: 0 / 27