/// - Art - #include <bits/stdc++.h> #define el cout << '\n' #define MASK(x) (1 << (x)) #define BIT(i, x) ((x) >> (i) & 1) #define corved(x) ((BIT(0, x) && BIT(1, x)) || (BIT(2, x) && BIT(3, x))) #define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i) #define REV(i, b, a) for (int i = (b), _a = (a); i >= _a; --i) #define REP(i, c) for (int i = 0, _c = (c); i < _c; ++i) const int N = 1e6 + 7; using namespace std; pair<int, int> p[N]; vector<pair<int, int>> row[N], col[N]; int state[N]; struct Data { int coord, sz; bool type; /// 0/1: row/col Data(int _coord = 0, int _sz = 0, bool _type = 0) { coord = _coord; sz = _sz; type = _type; } bool operator() (Data &a, Data &b) { return a.sz > b.sz; } }; bool lamp[N]; /// 0: Left, 1: Right /// 2: Up, 3: Down int main() { #define name "slamp" if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); } ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n; cin >> n; FOR (i, 1, n) { int x, y; cin >> x >> y; p[i] = make_pair(x, y); row[x].emplace_back(y, i); col[y].emplace_back(x, i); } // sort(p + 1, p + n + 1); // priority_queue<Data, vector<Data>> Q; // FOR (x, 1, 1e6) if (!row[x].empty()) { // row[x].emplace_back() // } FOR (y, 1, 1e6) { sort(col[y].begin(), col[y].end()); } FOR (x, 1, 1e6) if (!row[x].empty()) { sort(row[x].begin(), row[x].end()); FOR (i, 1, row[x].size() - 2) { int id = row[x][i].second; state[id] |= MASK(0) | MASK(1); } lamp[row[x][0].second] = 1; for (pair<int, int> &info : col[p[row[x][0].second].second]) { int id = info.second; if (info.first < x) { state[id] |= MASK(2); } else if (info.first > x) { state[id] |= MASK(3); } } if (row[x].size() >= 2) { lamp[row[x].back().second] = 1; for (pair<int, int> &info : col[p[row[x].back().second].second]) { int id = info.second; if (info.first < x) { state[id] |= MASK(2); } else if (info.first > x) { state[id] |= MASK(3); } } } } // cout << bitset<4>(state[7]), el; FOR (i, 1, n) if (lamp[i] && corved(state[i])) { lamp[i] = 0; int x = p[i].first, y = p[i].second; for (pair<int, int> &info : row[x]) { int id = info.second; if (info.first < y) { state[id] ^= MASK(0); } else if (info.first > y) { state[id] ^= MASK(1); } } for (pair<int, int> &info : col[y]) { int id = info.second; if (info.first < x) { state[id] ^= MASK(2); } else if (info.first > x) { state[id] ^= MASK(3); } } } FOR (i, 1, n) { cout << (lamp[i] || !corved(state[i])); } el; return 0; } /* 9 1 1 1 2 1 3 2 1 2 2 2 3 3 1 3 2 3 3 */ /* 8 1 5 3 5 6 7 6 5 6 1 3 7 6 3 5 5 */

Main.cpp: In function 'int main()':
Main.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen(name".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:46:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         freopen(name".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~