func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize( O3 )   using namespace std;   using ll = long long;   using vi = vector<int>;   using pii = pair<int, int>;   const int BSZ = 600;   const int N = 100228;   const int LG = 17;   int n, m;   vector<vi> g;   vi pred;   vi in, out;   int timer;   int up[LG][N];   vi ts;   vi evs;   vi sgn;   vector<bool> alive;   vi cnt;   vi dif;   vector<bool> any;   int cur_add;   vi ans;   vi bkt[2 * N];   vi srt[2 * BSZ];   void dfs(int v) {     in[v] = timer++;     for (int to : g[v]) {       dfs(to);     }     out[v] = timer++;   }   bool upper(int u, int v) { return (in[u] <= in[v] && out[v] <= out[u]); }   int lca(int u, int v) {     if (in[u] > in[v]) {       swap(u, v);     }     if (upper(u, v)) {       return u;     }     for (int i = LG - 1; i >= 0; i--) {       if (!upper(up[i][u], v)) {         u = up[i][u];       }     }     return up[0][u];   }   void dfs_calc(int v) {     cnt[v] = !alive[v];     for (int to : g[v]) {       dfs_calc(to);       cnt[v] += cnt[to];       any[v] = any[v] | any[to];     }     dif[v] = ts[v] - cnt[v];     if (!any[v] && alive[v]) {       cur_add += (dif[v] < 0);     }   }   int32_t main() {     ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);     cin >> n >> m;     pred.resize(n, -1);     g.resize(n);     for (int i = 0; i < n - 1; i++) {       int p;       cin >> p;       --p;       pred[i + 1] = p;       g[p].push_back(i + 1);       up[0][i + 1] = p;     }     ts.resize(n);     for (auto& x : ts) {       cin >> x;     }     for (int j = 1; j < LG; j++) {       for (int i = 0; i < n; i++) {         up[j][i] = up[j - 1][up[j - 1][i]];       }     }     in.resize(n);     out.resize(n);     dfs(0);     evs.resize(m);     sgn.resize(m);     for (int i = 0; i < m; i++) {       auto& x = evs[i];       cin >> x;       sgn[i] = (x > 0 ? -1 : 1);       x = abs(x) - 1;     }     alive.resize(n, true);     cnt.resize(n);     dif.resize(n);     any.resize(n);     ans.resize(m, 0);     for (int lb = 0; lb < m; lb += BSZ) {       int rb = min(m, lb + BSZ);       vi guys(rb - lb);       fill((any).begin(), (any).end(), false);       for (int i = lb; i < rb; i++) {         guys[i - lb] = evs[i];         any[guys[i - lb]] = true;       }       sort((guys).begin(), (guys).end(),            [](int u, int v) { return (in[u] < in[v]); });       guys.reserve(2 * (int)((guys).size()));       for (int i = (int)((guys).size()) - 2; i >= 0; i--) {         guys.push_back(lca(guys[i], guys[i + 1]));       }       guys.push_back(0);       sort((guys).begin(), (guys).end(),            [](int u, int v) { return (in[u] < in[v]); });       guys.resize(unique((guys).begin(), (guys).end()) - guys.begin());       vi comp_pred((int)((guys).size()), -1);       vi st;       int edge_check = 0;       for (int i = 0; i < (int)((guys).size()); i++) {         while (!st.empty() && !upper(guys[st.back()], guys[i])) {           st.pop_back();         }         if (!st.empty()) {           comp_pred[i] = st.back();           edge_check++;         }         st.push_back(i);       }       assert(edge_check == (int)((guys).size()) - 1);       cur_add = 0;       dfs_calc(0);       for (int i = lb; i < rb; i++) {         ans[i] = cur_add;       }       for (int i = 0; i < (int)((guys).size()); i++) {         srt[i].clear();       }       for (int i = 0; i < 2 * N; i++) {         bkt[i].clear();       }       for (int i = 0; i < (int)((guys).size()); i++) {         int u = guys[i];         bool st = alive[u];         int udif = dif[u];         for (int j = lb; j < rb; j++) {           if (upper(u, evs[j])) {             udif += sgn[j];           }           if (evs[j] == u) {             st = !st;           }           if (st) {             ans[j] += (udif < 0);           }         }         if (i) {           int anc = guys[comp_pred[i]];           int v = pred[u];           if (anc != v) {             while (v != anc) {               if (alive[v]) {                 bkt[dif[v] + N].push_back(i);               }               v = pred[v];             }           }         }       }       for (int i = 0; i < 2 * N; i++) {         for (int who : bkt[i]) {           srt[who].push_back(i - N);         }       }       for (int i = 0; i < (int)((guys).size()); i++) {         auto u = guys[i];         auto& difs = srt[i];         vector<pii> pref;         pref.reserve((int)((difs).size()));         for (auto x : difs) {           if (pref.empty()) {             pref.push_back({x, 1});           } else if (x != pref.back().first) {             pref.push_back({x, pref.back().second + 1});           } else {             pref.back().second++;           }         }         int pt = (int)((pref).size());         while (pt > 0 && pref[pt - 1].first >= 0) {           pt--;         }         int bound = 0;         for (int j = lb; j < rb; j++) {           if (upper(u, evs[j])) {             bound -= sgn[j];             if (pt < (int)((pref).size()) && pref[pt].first < bound) {               pt++;             }             if (pt > 0 && pref[pt - 1].first >= bound) {               pt--;             }           }           ans[j] += (pt ? pref[pt - 1].second : 0);         }       }       for (int i = lb; i < rb; i++) {         int u = evs[i];         alive[u] = !alive[u];       }     }     for (int i = 0; i < m; i++) {       cout << ans[i] <<    ;     }   }   