Submission #190119

#	Time	Username	Problem	Language	Result	Execution time	Memory
190119		fedoseevtimofey	Port Facility (JOI17_port_facility)	C++14	22 / 100	155 ms	32756 KiB

port_facility

#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <random>
#include <iomanip>
#include <cassert>
#include <complex>
#include <functional>
 
using namespace std;
 
typedef long long ll;

const int md = 1e9 + 7;

void add(int &a, int b) {
  a += b;
  if (a >= md) a -= md;
}

int mul(int a, int b) {
  return ((ll)a * b) % md;
}

int power(int a, ll b) {
  int res = 1;
  while (b > 0) {
    if (b & 1) res = mul(res, a);
    a = mul(a, a);
    b >>= 1;
  }
  return res;
}

int inv(int a) {
  return power(a, md - 2);
}

const int N = 2e3 + 7;

vector <int> g[N];
int col[N];

void dfs(int u) {
  for (auto v : g[u]) {
    if (col[v] == -1) {
      col[v] = col[u] ^ 1;
      dfs(v);
    } else if (col[v] != (col[u] ^ 1)) {
      cout << "0\n";
      exit(0);
    }
  }
}

int main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
  freopen("input.txt", "r", stdin);
#endif
  int n;
  cin >> n;
  vector <int> a(n), b(n);
  for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < n; ++j) {
      if (a[i] < a[j] && a[j] < b[i] && b[i] < b[j]) {
        g[i].push_back(j);
        g[j].push_back(i);
      } else if (a[j] < a[i] && a[i] < b[j] && b[j] < b[i]) {
        g[i].push_back(j);
        g[j].push_back(i);
      }
    }
  }
  fill(col, col + n, -1);
  int cmp = 0;
  for (int i = 0; i < n; ++i) {
    if (col[i] == -1) {
      ++cmp;
      col[i] = 0;
      dfs(i);
    }
  }
  int ans = power(2, cmp);
  cout << ans << '\n';
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 0 / 56
• Subtask 4: 0 / 22