func_code_string: #include <bits/stdc++.h>   using namespace std;   class sparse_table {     vector<int> values;     vector<int> maxk;     vector<vector<int> > st;     void build(const vector<int>& a) {       values = a;       int n = a.size();       st.resize(maxk[n] + 1);       st[0].resize(n);       for (int i = 0; i < n; i++) st[0][i] = i;       for (int i = 1; i <= maxk[n]; i++) {         st[i].resize(n - (1 << i) + 1);         for (int j = 0; j < (int)st[i].size(); j++) {           if (values[st[i - 1][j]] < values[st[i - 1][j + (1 << (i - 1))]])             st[i][j] = st[i - 1][j];           else             st[i][j] = st[i - 1][j + (1 << (i - 1))];         }       }     }       public:     sparse_table(const vector<int>& vec) {       int n = vec.size();       maxk.resize(n + 1, 0);       for (int i = 2; i < n + 1; i++) maxk[i] = maxk[i / 2] + 1;       build(vec);     }     sparse_table() {}     int get(int l, int r) {       if (values[st[maxk[r - l]][l]] <           values[st[maxk[r - l]][r - (1 << maxk[r - l])]])         return st[maxk[r - l]][l];       else         return st[maxk[r - l]][r - (1 << maxk[r - l])];     }   };   int n;   vector<vector<int> > graph;   vector<int> vec;   vector<int> height;   vector<int> first;   vector<int> tin, tout, parent;   int cur_time = 0;   void dfs(int u, int par, int hg) {     height[u] = hg;     vec.push_back(u);     first[u] = vec.size() - 1;     tin[u] = cur_time++;     parent[u] = par;     for (int v : graph[u])       if (v != par) {         vec.push_back(u);         dfs(v, u, hg + 1);       }     tout[u] = cur_time++;   }   sparse_table st;   void precalc_lca() {     vec.clear();     height.clear();     first.clear();     height.resize(n);     first.resize(n);     tin.resize(n);     tout.resize(n);     parent.resize(n);     dfs(0, -1, 0);     vector<int> to_st(vec.size());     for (int i = 0; i < (int)vec.size(); i++) to_st[i] = height[vec[i]];     st = sparse_table(to_st);   }   int lca(int u, int v) {     int a = min(first[u], first[v]);     int b = max(first[u], first[v]);     return vec[st.get(a, b + 1)];   }   int dist(int u, int v) { return height[u] + height[v] - 2 * height[lca(u, v)]; }   bool is_child(int u, int v) { return tin[u] <= tin[v] && tout[v] <= tout[u]; }   int c1 = 0, c2 = 0, x = 0;   int add_vertex(int v) {     if (c1 == c2) {       if (dist(c1, v) == x + 1) {         x++;         if (is_child(c1, v)) {           auto it = upper_bound(               graph[c1].begin(), graph[c1].end(), v,               [](const int& i, const int& j) -> bool { return tin[i] < tin[j]; });           assert(it != graph[c1].begin());           it--;           c2 = *it;         } else {           c2 = parent[c1];         }       }     } else {       if (dist(c1, v) == x + 1) {         c1 = c2;       } else if (dist(c2, v) == x + 1) {         c2 = c1;       }     }     if (c1 == c2) {       return 2 * x;     } else {       return 2 * x - 1;     }   }   int main() {     cin >> n;     graph.resize(n);     for (int i = 1; i < n; i++) {       int a;       cin >> a;       a--;       graph[a].push_back(i);       graph[i].push_back(a);     }     precalc_lca();     for (int i = 1; i < n; i++) {       cout << add_vertex(i) <<    ;     }     cout << endl;     return 0;   }   