func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long int N = 4e5 + 2, inf = 1e12 + 7;   vector<pair<int, int> > vec[N];   pair<int, pair<int, int> > edg[N];   long long int n, dis[N], dis2[N], st[N], ed[N];   long long int T[2 * N], lzy[2 * N], tim;   void dfs(int u, int pr) {     st[u] = ++tim;     for (auto x : vec[u]) {       int v = x.first, w = x.second;       if (v == pr) continue;       dis[v] = dis[u] + w;       dfs(v, u);     }     ed[u] = tim;   }   void push_down(int nod, int lo, int hi) {     T[nod] += lzy[nod];     if (lo != hi) {       lzy[2 * nod] += lzy[nod];       lzy[2 * nod + 1] += lzy[nod];     }     lzy[nod] = 0;   }   void updt(int nod, int lo, int hi, int l, int r, int vl) {     if (lzy[nod]) push_down(nod, lo, hi);     if (hi < l || lo > r || lo > hi) return;     if (lo >= l && hi <= r) {       T[nod] += vl;       if (lo != hi) {         lzy[2 * nod] += vl;         lzy[2 * nod + 1] += vl;       }       return;     }     int md = (lo + hi) >> 1;     updt(2 * nod, lo, md, l, r, vl);     updt(2 * nod + 1, md + 1, hi, l, r, vl);     T[nod] = min(T[2 * nod], T[2 * nod + 1]);   }   long long int qry(int nod, int lo, int hi, int l, int r) {     if (lzy[nod]) push_down(nod, lo, hi);     if (hi < l || lo > r || lo > hi) return inf;     if (lo >= l && hi <= r) return T[nod];     int md = (lo + hi) >> 1;     return min(qry(2 * nod, lo, md, l, r), qry(2 * nod + 1, md + 1, hi, l, r));   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int tc = 1, t = 0;     while (tc--) {       int q;       cin >> n >> q;       for (int i = 1; i < n; i++) {         int u, v, c;         cin >> u >> v >> c;         vec[u].push_back(make_pair(v, c));         edg[i] = make_pair(u, make_pair(v, c));       }       for (int i = n; i < n + n - 1; i++) {         int u, v, c;         cin >> u >> v >> c;         edg[i] = make_pair(u, make_pair(v, c));         dis2[u] = c;       }       dfs(1, -1);       for (int i = 1; i <= n; i++) updt(1, 1, n, st[i], st[i], dis[i] + dis2[i]);       while (q--) {         int typ;         cin >> typ;         if (typ == 1) {           int id, w;           cin >> id >> w;           int u = edg[id].first, v = edg[id].second.first;           int c = edg[id].second.second;           if (id < n) {             updt(1, 1, n, st[v], ed[v], -c);             updt(1, 1, n, st[v], ed[v], w);             edg[id].second.second = w;           } else {             updt(1, 1, n, st[u], st[u], -c);             updt(1, 1, n, st[u], st[u], w);             edg[id].second.second = w;             dis2[u] = w;           }         } else {           int u, v;           cin >> u >> v;           if (st[v] >= st[u] && ed[u] >= ed[v]) {             cout << qry(1, 1, n, st[v], st[v]) - qry(1, 1, n, st[u], st[u]) +                         dis2[u] - dis2[v]                  <<   n ;           } else {             long long int rs = qry(1, 1, n, st[u], ed[u]);             rs -= qry(1, 1, n, st[u], st[u]);             rs += qry(1, 1, n, st[v], st[v]);             rs += dis2[u] - dis2[v];             cout << rs <<   n ;           }         }       }     }     return 0;   }   