Submission #798969

#	Time	Username	Problem	Language	Result	Execution time	Memory
798969		vjudge1	Port Facility (JOI17_port_facility)	C++17	0 / 100	1 ms	340 KiB

port_facility

#include<bits/stdc++.h>

using namespace std;
using ll = long long;

const int N = 2e3 + 10;
const int MOD = 1e9 + 7;

int n;
vector<int> g[N];
pair<int, int> bounds[N];

int cl[N];
bool flag = 0;
void dfs(int s, int p = -1) {
    cl[s] = ((p == -1 || cl[p] == 2) ? 1 : 2);
    for(int to : g[s]) {
        if(!cl[to]) dfs(to, s);
        flag |= (cl[to] == cl[s]);
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    cin >> n;
    for(int i = 0; i < n; i++) 
        cin >> bounds[i].first >> bounds[i].second;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < n; j++) {
            if(bounds[i].first < bounds[j].first & bounds[j].first < bounds[i].second && bounds[i].second < bounds[j].second) 
                g[i].push_back(j);
            if(bounds[i].first > bounds[j].first & bounds[j].first > bounds[i].second && bounds[i].second > bounds[j].second) 
                g[i].push_back(j);
        }
    }
    int ans = 1;
    for(int i = 0; i < n; i++) {
        if(cl[i]) continue;
        dfs(i);
        ans = (ans * 2) % MOD;
    }
    if(flag) ans = 0;
    cout << ans;
}

Compilation message (stderr)

port_facility.cpp: In function 'int main()':
port_facility.cpp:31:32: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   31 |             if(bounds[i].first < bounds[j].first & bounds[j].first < bounds[i].second && bounds[i].second < bounds[j].second)
      |                ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
port_facility.cpp:33:32: warning: suggest parentheses around comparison in operand of '&' [-Wparentheses]
   33 |             if(bounds[i].first > bounds[j].first & bounds[j].first > bounds[i].second && bounds[i].second > bounds[j].second)
      |                ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~

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