// Author: 4uckd3v - Nguyen Cao Duc #include <bits/stdc++.h> using namespace std; #define all(x) (x).begin(), (x).end() typedef long long ll; typedef pair<int, int> ii; const int MAX_N = 1e5; const int MOD = 1e9 + 7; const ll INF = 1e18; struct SegmentTree { vector<ll> seg, lazy; int n; void down(int node) { for (int i = 0; i < 2; i++) { seg[node << 1 | i] += lazy[node]; lazy[node << 1 | i] += lazy[node]; }; lazy[node] = 0; }; void assign(int pos, ll val) { int l = 1, r = n, node = 1; while (l < r) { int mid = (l + r) >> 1; if (lazy[node]) down(node); if (pos <= mid) { node <<= 1; r = mid; } else { (node <<= 1) |= 1; l = mid + 1; }; }; seg[node] = val; while (node > 1) { node >>= 1; seg[node] = min(seg[node << 1], seg[node << 1 | 1]); }; }; void update(int node, int l, int r, int u, int v, int val) { if (l > v || r < u) return; if (l >= u && r <= v) { seg[node] += val; lazy[node] += val; return; }; int mid = (l + r) >> 1; if (lazy[node]) down(node); update(node << 1, l, mid, u, v, val); update(node << 1 | 1, mid + 1, r, u, v, val); seg[node] = min(seg[node << 1], seg[node << 1 | 1]); }; void update(int l, int r, int val) { update(1, 1, n, l, r, val); }; ll getMin() { return seg[1]; }; SegmentTree() {}; SegmentTree(int n) : n(n) { seg.assign(4 * n + 5, INF); lazy.assign(4 * n + 5, 0); }; }; struct FenwickTree { int n; vector<ll> bit; void update(int pos, int val) { for (; pos <= n; pos += pos & (-pos)) bit[pos] += val; }; ll get(int pos) { ll ret = 0; for (; pos > 0; pos -= pos & (-pos)) ret += bit[pos]; return ret; }; FenwickTree() {}; FenwickTree(int n) : n(n) { bit.assign(n + 5, 0); }; }; int n, q, timer, lg; int par[MAX_N + 5], sz[MAX_N + 5], tin[MAX_N + 5], tout[MAX_N + 5], edgeWeight[MAX_N + 5]; int up[MAX_N + 5][18]; bool del[MAX_N + 5], grap[MAX_N + 5]; ll f[MAX_N + 5]; vector<int> centNode[MAX_N + 5]; vector<ii> adj[MAX_N + 5]; SegmentTree seg[MAX_N + 5]; FenwickTree bit; void preDfs(int u, int p) { tin[u] = ++timer; up[u][0] = p; for (int i = 1; i <= lg; i++) up[u][i] = up[up[u][i - 1]][i - 1]; for (ii e : adj[u]) { int v = e.first, w = e.second; if (v == p) continue; edgeWeight[v] = w; f[v] = f[u] + w; preDfs(v, u); }; tout[u] = timer; }; bool isAncestor(int u, int v) { return tin[u] <= tin[v] && tout[u] >= tout[v]; }; int __lca(int u, int v) { if (isAncestor(u, v)) return u; if (isAncestor(v, u)) return v; for (int i = lg; i >= 0; i--) if (!isAncestor(up[u][i], v)) u = up[u][i]; return up[u][0]; }; ll dist(int u, int v) { return f[u] + f[v] - f[__lca(u, v)] * 2; }; void calcSize(int u, int p) { sz[u] = 1; for (ii e : adj[u]) { int v = e.first; if (v == p || del[v]) continue; calcSize(v, u); sz[u] += sz[v]; }; }; int findCentroid(int u, int p, int n) { for (ii e : adj[u]) { int v = e.first; if (v == p || del[v]) continue; if (sz[v] * 2 > n) return findCentroid(v, u, n); }; return u; }; void collectNode(int root, int u, int p) { centNode[root].push_back(u); for (ii e : adj[u]) { int v = e.first; if (v == p || del[v]) continue; collectNode(root, v, u); }; }; void decompose(int u, int p) { calcSize(u, u); int centroid = findCentroid(u, u, sz[u]); par[centroid] = p; del[centroid] = true; collectNode(centroid, centroid, centroid); sort(all(centNode[centroid]), [&](int u, int v) { return tin[u] < tin[v]; }); for (ii e : adj[centroid]) { int v = e.first; if (del[v]) continue; decompose(v, centroid); }; }; ll sumPath(int u, int v) { return bit.get(tin[u]) + bit.get(tin[v]) - bit.get(tin[__lca(u, v)]) * 2; }; ll query(int u) { ll res = INF; for (int v = u; v != 0; v = par[v]) { res = min(res, sumPath(u, v) + seg[v].getMin()); }; return res; }; int findLeft(int x, const vector<int>& data) { int l = 0, r = (int)data.size() - 1, pos = -1; while (l <= r) { int mid = (l + r) >> 1; if (tin[data[mid]] >= x) { pos = mid; r = mid - 1; } else l = mid + 1; }; return pos; }; int findRight(int x, const vector<int>& data) { int l = 0, r = (int)data.size() - 1, pos = -1; while (l <= r) { int mid = (l + r) >> 1; if (tin[data[mid]] <= x) { pos = mid; l = mid + 1; } else r = mid - 1; }; return pos; }; void updateGrap(int u) { grap[u] ^= 1; for (int v = u; v != 0; v = par[v]) { int idx = findLeft(tin[u], centNode[v]) + 1; ll val = grap[u] ? sumPath(u, v) : INF; seg[v].assign(idx, val); }; }; void updateWeight(int u, int delta) { for (int v = par[u]; v != 0; v = par[v]) { int l = findLeft(tin[u], centNode[v]) + 1; if (l == 0) continue; int r = findRight(tout[u], centNode[v]) + 1; seg[v].update(l, r, delta); }; }; int main() { ios_base::sync_with_stdio(0); cin.tie(0); if (fopen("MAIN.INP", "r")) { freopen("MAIN.INP", "r", stdin); freopen("MAIN.OUT", "w", stdout); }; cin >> n >> q; for (int i = 1; i < n; i++) { int u, v, w; cin >> u >> v >> w; adj[u].push_back(ii(v, w)); adj[v].push_back(ii(u, w)); }; lg = ceil(log2(n)); preDfs(1, 1); decompose(1, 0); int cntGrap = 0; for (int u = 1; u <= n; u++) { seg[u] = SegmentTree(centNode[u].size()); }; bit = FenwickTree(n); for (int u = 2; u <= n; u++) { bit.update(tin[u], edgeWeight[u]); bit.update(tout[u] + 1, -edgeWeight[u]); }; while (q--) { int type, u; cin >> type >> u; if (type == 1) { cout << (cntGrap == 0 ? -1 : query(u)) << '\n'; }; if (type == 2) { cntGrap += (grap[u] ? -1 : 1); updateGrap(u); }; if (type == 3) { int v, newWeight; cin >> v >> newWeight; if (isAncestor(v, u)) swap(u, v); int delta = -edgeWeight[v] + newWeight; bit.update(tin[v], delta); bit.update(tout[v] + 1, -delta); updateWeight(v, delta); edgeWeight[v] = newWeight; }; }; };

Main.cpp: In function 'int main()':
Main.cpp:262:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  262 |         freopen("MAIN.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:263:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  263 |         freopen("MAIN.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~