#include <bits/stdc++.h> #define int long long #define fi first #define se second #define pii pair<int, int> #define all(a) a.begin(), a.end() using namespace std; #ifdef LOCAL #include "C:\Users\Dell\Downloads\template\template\icpc-notebook\Utilities\debug.h" #else #define debug(...) 42 #endif const int mn = 5e5 + 5, mod = 1e9 + 7, inf = 2e9; int n, x[mn], y[mn], cnt_x[mn], cnt_y[mn], max_x[mn], max_y[mn], min_x[mn], min_y[mn]; void trau(){ for(int i = 0; i < n; i++){ max_x[x[i]] = - inf, max_y[y[i]] = - inf; min_x[x[i]] = inf, min_y[y[i]] = inf; } int ans = -1; for(int mask = 0; mask < (1 << n); mask++){ vector <int> on; for(int i = 0; i < n; i++){ if(mask & (1 << i)) on.push_back(i); } for(auto i : on){ cnt_x[x[i]] ++; cnt_y[y[i]] ++; max_x[x[i]] = max(max_x[x[i]], y[i]); min_x[x[i]] = min(min_x[x[i]], y[i]); max_y[y[i]] = max(max_y[y[i]], x[i]); min_y[y[i]] = min(min_y[y[i]], x[i]); } bool ok = true; for(auto i : on) if(cnt_x[x[i]] > 2 || cnt_y[y[i]] > 2) ok = false; if(ok){ for(int i = 0; i < n; i++){ if((max_x[x[i]] > y[i] && y[i] > min_x[x[i]]) || (max_y[y[i]] > x[i] && x[i] > min_y[y[i]]) || mask & (1 << i)) continue; ok = false; } } for(auto i : on){ cnt_x[x[i]] --; cnt_y[y[i]] --; max_x[x[i]] = - inf, max_y[y[i]] = - inf; min_x[x[i]] = inf, min_y[y[i]] = inf; } if(ok){ ans = mask; break; } } for(int i = 0; i < n; i++){ if(ans & (1 << i)) cout << 1; else cout << 0; } cout << '\n'; } void solve() { cin >> n; for(int i = 0; i < n; i++) cin >> x[i] >> y[i]; trau(); } signed main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr); #define task "CSCH" if (fopen(task".INP", "r")) { freopen(task".INP", "r", stdin); freopen(task".OUT", "w", stdout); } int t = 1; // cin >> t; while (t--) solve(); return 0; } // Don't wanna lose anymore T_T // Never let me go - Kazuo Ishiguro

Main.cpp: In function 'int main()':
Main.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         freopen(task".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:80:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |         freopen(task".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~