func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxN = 100100;   const int maxM = maxN << 1;   const int maxB = 17;   int n, Q, Log[maxN];   int edgecnt = -1, Head[maxN], Next[maxM], V[maxM], W[maxM], Dst[maxN];   class Tree {    public:     int root, Dep[maxN], Fa[maxN], Dst[maxN], Mx[maxN], ST[maxB][maxN],         Mxd[maxB][maxN], dfncnt, dfn[maxN], lst[maxN];     int lcnt, Mark[maxN];     pair<int, int> Leaf[maxN];     void dfs_init(int u, int fa) {       Dep[u] = 0;       ST[0][u] = fa;       for (int i = Head[u]; i != -1; i = Next[i])         if (V[i] != fa) {           dfs_init(V[i], u);           if (Dep[V[i]] + W[i] > Dep[u]) Mx[u] = V[i], Dep[u] = Dep[V[i]] + W[i];         }       return;     }     void dfs_push(int u, int fa, int w) {       Dep[u] = Dep[fa] + 1;       dfn[u] = ++dfncnt;       Mxd[0][dfncnt] = Dst[u];       if (Mx[u] == 0)         Leaf[++lcnt] = make_pair(w, u);       else {         Fa[Mx[u]] = u;         for (int i = Head[u]; i != -1; i = Next[i])           if (V[i] != fa)             Dst[V[i]] = Dst[u] + W[i],             dfs_push(V[i], u, (V[i] == Mx[u]) ? w + W[i] : W[i]);       }       lst[u] = dfncnt;       return;     }     void Init(int r) {       root = r;       dfs_init(root, 0);       Dep[root] = 1;       Dst[root] = 0;       dfs_push(root, 0, 0);       for (int i = 1; i < maxB; i++)         for (int j = 1; j <= n; j++) ST[i][j] = ST[i - 1][ST[i - 1][j]];       sort(&Leaf[1], &Leaf[lcnt + 1]);       reverse(&Leaf[1], &Leaf[lcnt + 1]);       for (int i = 1; i <= lcnt; i++) Leaf[i].first += Leaf[i - 1].first;       for (int i = 1; i <= lcnt; i++) {         int now = Leaf[i].second;         while (now) Mark[now] = i, now = Fa[now];       }       for (int i = 1; i < maxB; i++)         for (int j = 1; j + (1 << (i)) - 1 <= n; j++)           Mxd[i][j] = max(Mxd[i - 1][j], Mxd[i - 1][j + (1 << (i - 1))]);       return;     }     int LCA(int u, int v) {       if (Dep[u] < Dep[v]) swap(u, v);       for (int i = maxB - 1; i >= 0; i--)         if (ST[i][u] && Dep[ST[i][u]] >= Dep[v]) u = ST[i][u];       if (u == v) return u;       for (int i = maxB - 1; i >= 0; i--)         if (ST[i][u] && ST[i][v] && ST[i][u] != ST[i][v])           u = ST[i][u], v = ST[i][v];       return ST[0][u];     }     int GET(int u, int cnt) {       cnt = min(cnt * 2 - 1, lcnt);       if (Mark[u] <= cnt) return Leaf[cnt].first;       int ret = Leaf[cnt - 1].first;       int now = u;       for (int i = maxB - 1; i >= 0; i--)         if (ST[i][now] && Mark[ST[i][now]] > cnt) now = ST[i][now];       now = ST[0][now];       int l = dfn[u], r = lst[u], lg = Log[r - l + 1];       int mxd = max(Mxd[lg][l], Mxd[lg][r - (1 << (lg)) + 1]);       ret = ret + mxd - Dst[now];       return max(ret, Leaf[cnt].first + mxd - Dst[Leaf[Mark[now]].second]);     }   };   Tree T1, T2;   void Add_Edge(int u, int v, int w);   void Bfs(int S);   int main() {     for (int i = 2; i < maxN; i++) Log[i] = Log[i >> 1] + 1;     scanf( %d%d , &n, &Q);     memset(Head, -1, sizeof(Head));     for (int i = 1; i < n; i++) {       int u, v, w;       scanf( %d%d%d , &u, &v, &w);       Add_Edge(u, v, w);       Add_Edge(v, u, w);     }     int S, T;     Bfs(1);     S = 1;     for (int i = 1; i <= n; i++)       if (Dst[S] < Dst[i]) S = i;     Bfs(S);     T = 1;     for (int i = 1; i <= n; i++)       if (Dst[T] < Dst[i]) T = i;     T1.Init(S);     T2.Init(T);     int lstans = 0;     while (Q--) {       int x, y;       scanf( %d%d , &x, &y);       x = (x + lstans - 1) % n + 1;       y = (y + lstans - 1) % n + 1;       printf( %d n , lstans = max(T1.GET(x, y), T2.GET(x, y)));     }     return 0;   }   void Add_Edge(int u, int v, int w) {     Next[++edgecnt] = Head[u];     Head[u] = edgecnt;     V[edgecnt] = v;     W[edgecnt] = w;     return;   }   void Bfs(int S) {     static int vis[maxN], Qu[maxN];     memset(vis, 0, sizeof(vis));     int l = 1, r = 1;     Qu[1] = S;     Dst[S] = 0;     vis[S] = 1;     while (l <= r)       for (int u = Qu[l++], i = Head[u]; i != -1; i = Next[i])         if (vis[V[i]] == 0) Dst[Qu[++r] = V[i]] = Dst[u] + W[i], vis[V[i]] = 1;     return;   }   