func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 2e5 + 50;   int n, cnt;   pair<int, int> poi[maxn], A[maxn];   void solve(int l, int r) {     if (l > r) return;     int mid = (l + r) >> 1;     for (int i = l; i <= r; i++)       poi[++cnt] = (pair<int, int>){A[mid].first, A[i].second};     solve(l, mid - 1);     solve(mid + 1, r);   }   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) scanf( %d%d , &A[i].first, &A[i].second);     sort(A + 1, A + 1 + n);     solve(1, n);     sort(poi + 1, poi + 1 + cnt);     cnt = unique(poi + 1, poi + 1 + cnt) - poi - 1;     printf( %d n , cnt);     for (int i = 1; i <= cnt; i++) printf( %d %d n , poi[i].first, poi[i].second);     return 0;   }   