Submission #974880

#	Time	Username	Problem	Language	Result	Execution time	Memory
974880		yeediot	Port Facility (JOI17_port_facility)	C++17	0 / 100	5 ms	25432 KiB

port_facility

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
    int a,b;
    int operator()(const int x)const{
        return a*x+b;
    }
};
bool check(line l1,line l2,line l3){
    return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
const int mxn=1e6+5;
const int mod=1e9+7;
vector<int>adj[mxn];
int col[mxn];
int ans;
void dfs(int v,int pa){
    for(auto u:adj[v]){
        if(u==pa){
            continue;
        }
        if(col[u]){
            if(col[u]+col[v]!=3){
                ans=0;
                return;
            }
        }
        else{
            col[u]=3-col[v];
            dfs(u,v);
        }
    }
}
signed main(){
    setio();
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n;
    cin>>n;
    vector<pii>v;
    ans=1;
    v.pb({0,0});
    vector<int>in[2*n+1],out[2*n+1];
    for(int i=1;i<=n;i++){
        int a,b;
        cin>>a>>b;
        v.pb({a,b});
        in[a].pb(i);
        out[b].pb(i);
    }
    set<pii>st;
    for(int i=1;i<=2*n;i++){
        for(auto x:in[i]){
            st.insert({i,x});
        }
        for(auto x:out[i]){
            auto it=st.upper_bound(make_pair(v[x].F,x));
            vector<pii>del;
            while(it!=st.end()){
                adj[x].pb(it->S);
                adj[it->S].pb(x);
                del.pb(*it);
                it=next(it);
            }
            for(auto p:del){
                st.erase(p);
            }
            st.erase({v[x].F,x});
        }
    }
    for(int i=1;i<=n;i++){
        if(!col[i]){
            col[i]=1;
            dfs(i,i);
            ans=ans*2%mod;
        }
    }
    cout<<ans<<'\n';
}
 /*
 input:
 
 */















 

Compilation message (stderr)

port_facility.cpp: In function 'void setIO(std::string)':
port_facility.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
port_facility.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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