#include<bits/stdc++.h> using namespace std; using ll = long long; const int mxn = 9 + 1e6; const int inf = 0x3f3f3f3f; const ll lnf = 0x3f3f3f3f3f3f3f3f; int n; vector<array<int, 2>> light; namespace SUB12 { bool check() { return (n <= 16); } void solve() { vector<int> mx_x(mxn, 0), mx_y(mxn, 0), mn_x(mxn, inf), mn_y(mxn, inf); vector<int> cnt_x(mxn, 0), cnt_y(mxn, 0); for (int msk = 0; msk < (1 << n); ++msk) { bool f = true; for (int i = 0; i < n; ++i) { if (msk >> i & 1) { mx_x[light[i][1]] = max(mx_x[light[i][1]], light[i][0]); mn_x[light[i][1]] = min(mn_x[light[i][1]], light[i][0]); mx_y[light[i][0]] = max(mx_y[light[i][0]], light[i][1]); mn_y[light[i][0]] = min(mn_y[light[i][0]], light[i][1]); if ((++cnt_x[light[i][0]]) > 2) { f = false; break; } if ((++cnt_y[light[i][1]]) > 2) { f = false; break; } } } if (!f) { for (int i = 0; i < n; ++i) { if (msk >> i & 1) { mx_x[light[i][1]] = 0; mn_x[light[i][1]] = inf; mx_y[light[i][0]] = 0; mn_y[light[i][0]] = inf; cnt_x[light[i][0]] = 0; cnt_y[light[i][1]] = 0; } } continue; } f = true; for (int i = 0; i < n; ++i) { if (!(mn_x[light[i][1]] <= light[i][0] && light[i][0] <= mx_x[light[i][1]]) && !(mn_y[light[i][0]] <= light[i][1] && light[i][1] <= mx_y[light[i][0]])) { f = false; break; } } if (f) { for (int i = 0; i < n; ++i) { if (msk >> i & 1) { cout << 1; } else { cout << 0; } } cout << "\n"; return; } for (int i = 0; i < n; ++i) { if (msk >> i & 1) { mx_x[light[i][1]] = 0; mn_x[light[i][1]] = inf; mx_y[light[i][0]] = 0; mn_y[light[i][0]] = inf; cnt_x[light[i][0]] = 0; cnt_y[light[i][1]] = 0; } } } } } namespace SUB3 { bool check() { vector<int> cnt(mxn); for (int i = 0; i < n; ++i) { if ((++cnt[light[i][0]]) > 2) { return false; } } return true; } void solve() { vector<int> mn_x(mxn, inf), mx_x(mxn, 0), posmn_x(mxn), posmx_x(mxn); for (int i = 0; i < n; ++i) { if (mn_x[light[i][1]] > light[i][0]) { mn_x[light[i][1]] = light[i][0]; posmn_x[light[i][1]] = i; } if (mx_x[light[i][1]] < light[i][0]) { mx_x[light[i][1]] = light[i][0]; posmx_x[light[i][1]] = i; } } vector<bool> used(n + 1); for (int i = 1; i < mxn; ++i) { if (mn_x[i] == inf) { continue; } used[posmn_x[i]] = used[posmx_x[i]] = true; } for (int i = 0; i < n; ++i) { cout << used[i]; } } } void _27augain(void) { cin >> n; light.resize(n); for (int i = 0; i < n; ++i) { cin >> light[i][0] >> light[i][1]; } if (SUB12::check()) { SUB12::solve(); return; } SUB3::solve(); } int32_t main() { #define TASK "SLAMP" cin.tie(0)->sync_with_stdio(0); if (fopen(TASK ".inp", "r")) { freopen(TASK ".inp", "r", stdin); freopen(TASK ".out", "w", stdout); } int testcase = 1; // cin >> testcase; while (testcase--) { _27augain(); } return 0; }

Main.cpp: In function 'int32_t main()':
Main.cpp:137:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |     freopen(TASK ".inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:138:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  138 |     freopen(TASK ".out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~