Submission #674471

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
674471	2022-12-24T13:12:00 Z	Sohsoh84	Dynamic Diameter (CEOI19_diameter)	C++17	0 / 100	544 ms	438480 KB

diameter

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 1e5 + 10;
const ll LOG = 20;
const ll INF = 1e18;

int n, q, t, cent_par[MAXN], H[MAXN], D[MAXN][LOG], sz[MAXN], 
    tin[MAXN][LOG], tout[MAXN][LOG], EV[MAXN], EU[MAXN];
ll w, lz[MAXN * LOG * 4], ans[MAXN], EW[MAXN];
pair<pll, pll> A[MAXN], sg[MAXN * LOG * 4];
vector<pll> adj[MAXN];
bool B[MAXN];

int dfs_sz(int v, int p) {
	sz[v] = 1;
	for (auto [u, w] : adj[v])
		if (!B[u] && u != p)
			sz[v] += dfs_sz(u, v);
	
	return sz[v];
}

int centroid(int v, int p, int tn) {
	for (auto [u, w] : adj[v])
		if (!B[u] && u != p && sz[u] * 2 > tn)
			return centroid(u, v, tn);

	return v;
}

void dfs(int v, int p, int lvl, ll d, int typ) {
	tin[v][lvl] = ++t;
	A[t] = {{d, typ}, {-INF, -1}};
	D[v][lvl] = D[p][lvl] + 1;

	for (auto [u, w] : adj[v])
		if (!B[u] && u != p)
			dfs(u, v, lvl, d + w, typ);

	tout[v][lvl] = t;
}

void build_tree(int v, int p, int lvl) {
	v = centroid(v, 0, dfs_sz(v, 0));
	cent_par[v] = p;
	H[v] = lvl;
	B[v] = true;

	tin[v][lvl] = ++t;
	D[v][lvl] = 0;
	A[t] = {{0, v}, {-INF, -1}};
	for (auto [u, w] : adj[v])
		if (!B[u])
			dfs(u, v, lvl, w, u);
	tout[v][lvl] = t;

	for (auto [u, w] : adj[v])
		if (!B[u])
			build_tree(u, v, lvl + 1);
}

inline void push(int v) {
	sg[v].X.X += lz[v];
	sg[v].Y.X += lz[v];
	if (v < (MAXN * LOG * 4))
		lz[v << 1] += lz[v], lz[v << 1 | 1] += lz[v];

	lz[v] = 0;
}

inline void add(pair<pll, pll>& a, pll b) {
	if (b.X > a.X.X) {
		if (b.Y != a.X.Y) a.Y = a.X;
		a.X = b;
	} else if (b.X > a.Y.X && b.Y != a.X.Y) {
		a.Y = b;
	}
}

inline pair<pll, pll> merge(pair<pll, pll> a, pair<pll, pll> b) {
	add(a, b.X);
	add(a, b.Y);
	return a;
}

void build(int l = 1, int r = t, int v = 1) {
	if (l == r) sg[v] = A[l];
	else {
		int mid = (l + r) >> 1;
		build(l, mid, v << 1);
		build(mid + 1, r, v << 1 | 1);
		sg[v] = merge(sg[v << 1], sg[v << 1 | 1]);
	}
}

void update(int ql, int qr, ll val, int l = 1, int r = t, int v = 1) {
	push(v);
	if (ql > r || qr < l) return;
	if (ql <= l && qr >= r) {
		lz[v] += val;
		push(v);
		return;
	}

	int mid = (l + r) >> 1;
	update(ql, qr, val, l, mid, v << 1);
	update(ql, qr, val, mid + 1, r, v << 1 | 1);
	sg[v] = merge(sg[v << 1], sg[v << 1 | 1]);
}

pair<pll, pll> query(int ql, int qr, int l = 1, int r = t, int v = 1) {
	push(v);
	if (ql > r || qr < l) return {{-INF, -INF}, {-INF, -INF - 1}};
	if (ql <= l && qr >= r) return sg[v];
	
	int mid = (l + r) >> 1;
	return merge(query(ql, qr, l, mid, v << 1),
			 query(ql, qr, mid + 1, r, v << 1 | 1));
}

set<pll> ans_st;

void update_ans(int v) {
	ans_st.erase({ans[v], v});
	auto e = query(tin[v][H[v]], tout[v][H[v]]);
	ans[v] = max(max(0ll, e.X.X), e.X.X + e.Y.X);
	ans_st.insert({ans[v], v});
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> q >> w;
	for (int i = 0; i < n - 1; i++) {
		cin >> EV[i] >> EU[i] >> EW[i];
		adj[EU[i]].push_back({EV[i], EW[i]});
		adj[EV[i]].push_back({EU[i], EW[i]});
	}

	build_tree(1, 0, 0);
	build();
	for (int v = 1; v <= n; v++) update_ans(v);

	ll last = 0;
	while (q--) {
		ll td, tw, ind, delta, rw, u, v;
		cin >> td >> tw;
		
		ind = (td + last) % (n - 1), rw = (tw + last) % w;
		u = EU[ind], v = EV[ind];
		delta = (rw - EW[ind]);
		EW[ind] = rw;

		if (H[u] > H[v]) swap(u, v);
		while (u) {
			int au = u, av = v, lvl = H[u];
			if (D[au][lvl] > D[av][lvl]) swap(au, av);

			update(tin[av][lvl], tout[av][lvl], delta);
			update_ans(u);
			u = cent_par[u];
		}

		last = ans_st.rbegin() -> X;
		cout << last << endl;
	}
	return 0;
}

Subtask #1
0 / 11.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	2 ms	2688 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #2
0 / 13.0

#	Verdict	Execution time	Memory	Grader output
1	Incorrect	2 ms	2688 KB	Output isn't correct
2	Halted	0 ms	0 KB	-

Subtask #3
0 / 7.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	2 ms	2684 KB	Output is correct
2	Correct	2 ms	2688 KB	Output is correct
3	Correct	2 ms	2772 KB	Output is correct
4	Correct	10 ms	2900 KB	Output is correct
5	Correct	42 ms	3900 KB	Output is correct
6	Correct	2 ms	2644 KB	Output is correct
7	Correct	2 ms	3028 KB	Output is correct
8	Correct	2 ms	3080 KB	Output is correct
9	Correct	3 ms	3028 KB	Output is correct
10	Correct	14 ms	3292 KB	Output is correct
11	Correct	57 ms	4360 KB	Output is correct
12	Correct	6 ms	6356 KB	Output is correct
13	Correct	7 ms	6484 KB	Output is correct
14	Correct	8 ms	6544 KB	Output is correct
15	Correct	25 ms	6832 KB	Output is correct
16	Correct	87 ms	7916 KB	Output is correct
17	Incorrect	121 ms	66708 KB	Output isn't correct
18	Halted	0 ms	0 KB	-