#include <bits/stdc++.h>
#define ll long long
#define task "GRAPEVINE"
using namespace std;
const int N = 1e5 + 16;
const ll INF = 1e18;
int n, q, u, v;
ll w;
vector < pair <int, ll> > adj[N];
namespace sub6 {
int h[N], up[N][26], timeDfs, in[N], out[N];
ll d[N], val[N];
void dfs(int k) {
timeDfs++;
in[k] = timeDfs;
for (auto v : adj[k]) {
if (v.first == up[k][0]) {
continue;
}
d[v.first] = d[k] + v.second;
val[v.first] = v.second;
h[v.first] = h[k] + 1;
up[v.first][0] = k;
for (int i = 1; i <= 20; i++) {
up[v.first][i] = up[up[v.first][i - 1]][i - 1];
}
dfs(v.first);
}
out[k] = timeDfs;
}
int lca(int u, int v) {
if (h[u] != h[v]) {
if (h[u] < h[v]) {
swap(u, v);
}
int k = h[u] - h[v];
for (int i = 0; (1 << i) <= k; i++) {
if (k >> i & 1) {
u = up[u][i];
}
}
}
if (u == v) {
return u;
}
int k = __lg(h[u]);
for (int i = k; i >= 0; i--) {
if (up[u][i] != up[v][i]) {
u = up[u][i];
v = up[v][i];
}
}
return up[u][0];
}
bool checkSubtree(int root, int k) {
return in[root] <= in[k] && out[k] <= out[root];
}
bool cmp(int a, int b) {
return in[a] < in[b];
}
int sz[N], parCd[N];
bool visited[N];
void countChild(int k, int p) {
sz[k] = 1;
for (auto v : adj[k]) {
if (v.first == p || visited[v.first]) {
continue;
}
countChild(v.first, k);
sz[k] += sz[v.first];
}
}
int findCentroid(int k, int p, int treeSz) {
for (auto v : adj[k]) {
if (v.first == p || visited[v.first]) {
continue;
}
if (sz[v.first] > (treeSz >> 1)) {
return findCentroid(v.first, k, treeSz);
}
}
return k;
}
int cd(int k) {
countChild(k, k);
int centroid = findCentroid(k, k, sz[k]);
visited[centroid] = true;
for (auto v : adj[centroid]) {
if (!visited[v.first]) {
parCd[cd(v.first)] = centroid;
}
}
return centroid;
}
struct Node{
long long d, answer;
bool state;
Node(){
d = answer = INF;
state = false;
}
Node operator + (const Node &rhs) const {
if(answer < rhs.answer) return *this;
return rhs;
}
};
struct Interval{
int root, numNode;
vector<int> node;
vector<Node> it;
vector<long long> lz;
inline void reSize(int n = 0){
it.resize(n << 2, Node());
lz.resize(n << 2, 0);
numNode = n;
}
inline void init(int id, int l, int r){
if(l == r){
it[id].d = d[node[l - 1]] + d[root] - 2 * d[lca(node[l - 1], root)];
return;
}
int mid = l + r >> 1;
init(id << 1, l, mid);
init(id << 1 | 1, mid + 1, r);
}
inline void push(int id){
long long &z = lz[id];
if(z == 0) return;
for (int v = id << 1; v <= (id << 1 | 1); v++) {
it[v].d += z;
it[v].answer += z;
it[v].answer = min(it[v].answer, INF);
lz[v] += z;
}
z = 0;
}
inline void modifyChange(int id, int l, int r, int p){
if(l == r){
it[id].state ^= 1;
if(it[id].state) it[id].answer = it[id].d;
else {
it[id].answer = INF;
}
return;
}
int mid = l + r >> 1;
push(id);
if(p <= mid)modifyChange(id << 1, l, mid, p);
else modifyChange(id << 1 | 1, mid + 1, r, p);
it[id] = it[id << 1] + it[id << 1 | 1];
}
inline void modifyRange(int id, int l,int r, int u, int v, int w){
if(l > v || r < u) return;
if(l >= u && r <= v){
it[id].d += w;
it[id].answer += w;
it[id].answer = min(it[id].answer, INF);
lz[id] += w;
return;
}
int mid = l + r >> 1;
push(id);
modifyRange(id << 1, l, mid, u, v, w);
modifyRange(id << 1 | 1, mid + 1, r, u, v, w);
it[id] = it[id << 1] + it[id << 1 | 1];
}
inline long long getDepth(int id, int l, int r, int p){
if(l == r) return it[id].d;
int mid = l + r >> 1;
push(id);
if(p <= mid) return getDepth(id << 1, l, mid, p);
else return getDepth(id << 1 | 1, mid + 1, r, p);
}
}tree[N];
int lowerBound(vector <int> &lst, int pos) {
int l = 0, r = lst.size() - 1, mid, res = lst.size();
while (l <= r) {
mid = l + r >> 1;
if (in[lst[mid]] >= pos) {
r = mid - 1;
res = mid;
}
else {
l = mid + 1;
}
}
res++;
return res;
}
int upperBound(vector <int> &lst, int pos) {
int l = 0, r = lst.size() - 1, mid, res = lst.size();
while (l <= r) {
mid = l + r >> 1;
if (in[lst[mid]] > pos) {
r = mid - 1;
res = mid;
}
else {
l = mid + 1;
}
}
res++;
return res;
}
ll query(int u) {
ll ans = INF;
int cur = u;
while (cur) {
int p = lowerBound(tree[cur].node, in[u]);
ans = min(ans, tree[cur].getDepth(1, 1, tree[cur].numNode, p) + tree[cur].it[1].answer);
cur = parCd[cur];
}
if (ans == INF) {
ans = -1;
}
return ans;
}
void change(int u) {
int cur = u;
while (cur) {
int p = lowerBound(tree[cur].node, in[u]);
tree[cur].modifyChange(1, 1, tree[cur].numNode, p);
cur = parCd[cur];
}
}
void path(int u, ll w) {
int cur = u;
while (cur) {
int L = lowerBound(tree[cur].node, in[u]);
int R = upperBound(tree[cur].node, out[u]);
R--;
if (L <= R && R <= tree[cur].numNode) {
if (checkSubtree(u, cur)) {
if (L - 1 >= 1) {
tree[cur].modifyRange(1, 1, tree[cur].numNode, 1, L - 1, w);
}
if (R + 1 <= tree[cur].numNode) {
tree[cur].modifyRange(1, 1, tree[cur].numNode, R + 1, tree[cur].numNode, w);
}
}
else {
tree[cur].modifyRange(1, 1, tree[cur].numNode, L, R, w);
}
}
cur = parCd[cur];
}
}
void solve() {
dfs(1);
cd(1);
for (int i = 1; i <= n; i++) {
u = i;
while (u) {
tree[u].node.push_back(i);
u = parCd[u];
}
}
for (int i = 1; i <= n; i++) {
sort(tree[i].node.begin(), tree[i].node.end(), cmp);
}
for (int i = 1; i <= n; i++) {
tree[i].reSize(tree[i].node.size());
tree[i].root = i;
tree[i].init(1, 1, tree[i].numNode);
}
while (q--) {
int type, u;
cin >> type >> u;
if (type == 1) {
cout << query(u) << "\n";
}
else if (type == 2) {
change(u);
}
else {
cin >> v >> w;
int p = h[u] < h[v] ? v : u;
path(p, w - val[p]);
val[p] = w;
}
}
}
}
int main() {
ios_base :: sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
cin >> n >> q;
for (int i = 1; i < n; i++) {
cin >> u >> v >> w;
adj[u].push_back({v, w});
adj[v].push_back({u, w});
}
sub6 :: solve();
return 0;
}
Compilation message (stderr)
Main.cpp: In function 'int main()':
Main.cpp:312:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
312 | freopen(task".inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:313:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
313 | freopen(task".out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~| # | Verdict | Execution time | Memory | Grader output |
|---|
| Fetching results... |
| # | Verdict | Execution time | Memory | Grader output |
|---|
| Fetching results... |
| # | Verdict | Execution time | Memory | Grader output |
|---|
| Fetching results... |
| # | Verdict | Execution time | Memory | Grader output |
|---|
| Fetching results... |
| # | Verdict | Execution time | Memory | Grader output |
|---|
| Fetching results... |
| # | Verdict | Execution time | Memory | Grader output |
|---|
| Fetching results... |