func_code_string: #include <bits/stdc++.h>   #pragma GCC optimize(2)   using namespace std;   int rd() {     int k = 0;     char c = getchar();     while (c >  9  || c <  0 ) c = getchar();     while (c >=  0  && c <=  9 ) k = k * 10 + c -  0 , c = getchar();     return k;   }   const int N = 300000, M = 600001;   int T, x, y, f[M], sx[M], sy[M];   long long ans;   vector<pair<int, int> > v[M << 1];   map<pair<int, int>, int> mp;   pair<int, int> p;   int F(int x) {     while (x != f[x]) x = f[x];     return x;   }   void Add(int x, int l, int r, int s, int t, pair<int, int> p) {     if (s <= l && r <= t) {       v[x].push_back(p);       return;     }     if (s <= ((l + r) >> 1)) Add((x << 1), l, ((l + r) >> 1), s, t, p);     if (((l + r) >> 1) < t) Add((x << 1 | 1), ((l + r) >> 1) + 1, r, s, t, p);   }   void Solve(int x, int l, int r) {     long long pre = ans;     stack<int> S;     for (int i = 0; i < v[x].size(); ++i) {       int a = F(v[x][i].first), b = F(v[x][i].second + N);       if (a == b) continue;       if (sx[a] + sy[a] > sx[b] + sy[b]) {         int t = a;         a = b, b = t;       }       ans -= (long long)sx[a] * sy[a] + (long long)sx[b] * sy[b],           f[a] = b, sx[b] += sx[a], sy[b] += sy[a];       ans += (long long)sx[b] * sy[b], S.push(a);     }     if (l == r)       printf( %lld  , ans);     else       Solve((x << 1), l, ((l + r) >> 1)),           Solve((x << 1 | 1), ((l + r) >> 1) + 1, r);     while (!S.empty()) {       int t = S.top(), z = f[t];       S.pop(), f[t] = t, sx[z] -= sx[t], sy[z] -= sy[t];     }     ans = pre;   }   int main() {     T = rd();     for (int i = 1; i <= T; ++i) {       x = rd(), y = rd(), p = make_pair(x, y);       if (mp.count(p))         Add(1, 1, T, mp[p], i - 1, p), mp.erase(p);       else         mp[p] = i;     }     for (auto t : mp) Add(1, 1, T, t.second, T, t.first);     for (int i = 1; i <= N; ++i) sx[f[i] = i] = 1;     for (int i = N + 1; i < M; ++i) sy[f[i] = i] = 1;     Solve(1, 1, T);     return 0;   }   