func_code_string: #include <bits/stdc++.h>   using namespace std;   const int size1 = 8e5;   const long long INF = 1e18;   const int INF1 = 1e9;   const double eps = 1e-5;   const long long mod = 1e9 + 7;   vector<vector<int> > graph(size1);   vector<vector<long long> > graph1(size1);   static int maxder[size1], minder[size1], d[size1], v[size1], u[size1], w[size1],       tin[size1], tout[size1];   static bool used[size1];   static long long ras[size1];   static long long tree[size1], tree1[size1], tree2[size1], tree3[size1],       w1[size1];   int num = 1;   int time1 = 0;   void dfs(int v) {     used[v] = true;     minder[v] = INF1;     for (int i = 0; i < graph[v].size(); i++) {       if (!used[graph[v][i]]) {         dfs(graph[v][i]);         minder[v] = min(minder[v], minder[graph[v][i]]);       }     }     maxder[v] = num;     num++;     minder[v] = min(minder[v], maxder[v]);   }   void dfs1(int v, long long ras1, int depth) {     time1++;     used[v] = true;     ras[maxder[v]] = ras1;     d[v] = depth;     tin[v] = time1;     for (int i = 0; i < graph[v].size(); i++) {       if (!used[graph[v][i]]) {         dfs1(graph[v][i], ras1 + graph1[v][i], depth + 1);       }     }     time1++;     tout[v] = time1;   }   void build_tree(int tl, int tr, int pos) {     if (tl == tr) {       tree[pos] = ras[tl];     } else {       int tm = (tl + tr) / 2;       build_tree(tl, tm, pos * 2);       build_tree(tm + 1, tr, pos * 2 + 1);       tree[pos] = tree[pos * 2] + tree[pos * 2 + 1];     }   }   void prib(int tl, int tr, int pos, int l, int r, long long x) {     if (l <= tl && tr <= r) {       tree1[pos] += x;     } else {       int tm = (tl + tr) / 2;       if (max(tl, l) <= min(tm, r)) {         prib(tl, tm, pos * 2, l, r, x);       }       if (max(tm + 1, l) <= min(tr, r)) {         prib(tm + 1, tr, pos * 2 + 1, l, r, x);       }       tree[pos] = tree[pos * 2] + tree[pos * 2 + 1] +                   tree1[pos * 2] * (tm - tl + 1) + tree1[pos * 2 + 1] * (tr - tm);     }   }   long long zn(int tl, int tr, int pos, int pos1, long long add) {     if (tl == pos1 && tr == pos1) {       return add + tree[pos] + tree1[pos];     } else {       int tm = (tl + tr) / 2;       if (tl <= pos1 && pos1 <= tm) {         return zn(tl, tm, pos * 2, pos1, add + tree1[pos]);       } else {         return zn(tm + 1, tr, pos * 2 + 1, pos1, add + tree1[pos]);       }     }   }   void build_tree1(int tl, int tr, int pos) {     if (tl == tr) {       tree2[pos] = ras[tl] + w1[tl];     } else {       int tm = (tl + tr) / 2;       build_tree1(tl, tm, pos * 2);       build_tree1(tm + 1, tr, pos * 2 + 1);       tree2[pos] = min(tree2[pos * 2], tree2[pos * 2 + 1]);     }   }   void upd2(int tl, int tr, int pos, int l, int r, long long x) {     if (l <= tl && tr <= r) {       tree3[pos] += x;     } else {       int tm = (tl + tr) / 2;       if (max(tl, l) <= min(tm, r)) {         upd2(tl, tm, pos * 2, l, r, x);       }       if (max(tm + 1, l) <= min(tr, r)) {         upd2(tm + 1, tr, pos * 2 + 1, l, r, x);       }       tree2[pos] = min(tree2[pos * 2] + tree3[pos * 2],                        tree2[pos * 2 + 1] + tree3[pos * 2 + 1]);     }   }   long long zn1(int tl, int tr, int pos, int l, int r, long long add) {     if (l <= tl && tr <= r) {       return add + tree3[pos] + tree2[pos];     } else {       int tm = (tl + tr) / 2;       long long ans = INF;       if (max(l, tl) <= min(r, tm)) {         ans = min(ans, zn1(tl, tm, pos * 2, l, r, add + tree3[pos]));       }       if (max(tm + 1, l) <= min(tr, r)) {         ans = min(ans, zn1(tm + 1, tr, pos * 2 + 1, l, r, add + tree3[pos]));       }       return ans;     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int n, q, i;     cin >> n >> q;     for (i = 1; i <= n - 1; i++) {       cin >> v[i] >> u[i] >> w[i];       graph[v[i]].push_back(u[i]);       graph[u[i]].push_back(v[i]);       graph1[v[i]].push_back(w[i]);       graph1[u[i]].push_back(w[i]);     }     dfs(1);     for (i = n; i <= 2 * n - 2; i++) {       cin >> v[i] >> u[i] >> w[i];       w1[maxder[v[i]]] = w[i];     }     memset(used, false, sizeof used);     dfs1(1, 0, 0);     build_tree(1, n, 1);     build_tree1(1, n, 1);     for (i = 1; i <= q; i++) {       int t, a, b;       cin >> t >> a >> b;       if (t == 1) {         if (a >= n) {           upd2(1, n, 1, maxder[v[a]], maxder[v[a]], b - w1[maxder[v[a]]]);           w1[maxder[v[a]]] = b;         } else {           int v1 = 0;           if (d[v[a]] > d[u[a]]) {             v1 = v[a];           } else {             v1 = u[a];           }           prib(1, n, 1, minder[v1], maxder[v1], b - w[a]);           upd2(1, n, 1, minder[v1], maxder[v1], b - w[a]);           w[a] = b;         }       } else {         long long res = INF;         if (max(tin[a], tin[b]) <= min(tout[a], tout[b]) && d[a] <= d[b]) {           res = min(res, zn(1, n, 1, maxder[b], 0) - zn(1, n, 1, maxder[a], 0));         }         res = min(res, zn1(1, n, 1, minder[a], maxder[a], 0) -                            zn(1, n, 1, maxder[a], 0) + zn(1, n, 1, maxder[b], 0));         cout << res << endl;       }     }     return 0;   }   