#include <bits/stdc++.h> #define int long long #define fi first #define se second #define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i) #define REV(i, a, b) for (int i = (a), _b = (b); i >= _b; --i) using namespace std; #define MAXN 1000005 int n; pair<int, int> a[MAXN]; vector<int> row[MAXN], col[MAXN]; int nxt[MAXN]; int prv[MAXN]; int dir[MAXN]; int ans[MAXN]; void Move(int u, int d) { int x, y; tie(x, y) = a[u]; if (dir[u] == 0) col[x].push_back(u); dir[u] += d; ans[u] = 1; if ((int)col[x].size() < 3) return; sort(col[x].begin(), col[x].end(), [&](const int &x, const int &y) { return a[x].se < a[y].se; }); u = col[x][1]; ans[u] = 0; col[x].erase(col[x].begin() + 1); if (dir[u] > 0) Move(nxt[u], dir[u]); if (dir[u] < 0) Move(prv[u], dir[u]); } void solve(){ cin >> n; FOR(i, 1, n) { cin >> a[i].fi >> a[i].se; row[a[i].se].push_back(i); } FOR(ROW, 1, 1000000) { vector<int> &R = row[ROW]; if (R.size() == 0) continue; sort(R.begin(), R.end(), [&](const int &x, const int &y) { return a[x].fi < a[y].fi; }); FOR(COL, 0, R.size() - 2) { nxt[R[COL]] = R[COL + 1]; prv[R[COL + 1]] = R[COL]; } Move(R[0], 1); Move(R.back(), -1); } FOR(i, 1, n) cout << ans[i]; } #define task "" int32_t main(){ if (fopen(task".inp","r")){ freopen(task".inp","r",stdin); freopen(task".out","w",stdout); } ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); solve(); return 0; }

Main.cpp: In function 'int32_t main()':
Main.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~