Submission #986940

#	Time	Username	Problem	Language	Result	Execution time	Memory
986940		amine_aroua	Port Facility (JOI17_port_facility)	C++17	100 / 100	2306 ms	189500 KiB

port_facility

#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
using namespace std;
#define pb push_back
#define nl '\n'
#define fore(i, y) for(int i = 0; i < y; i++)
#define forr(i, x, y) for(int i = x;i<=y;i++)
#define forn(i, y, x) for(int i = y; i >= x; i--)
const int MAXN = 2000010;
const int MOD = 1e9 + 7;
int ans = 1;
int n;
bool is_bipartite = 1;
int idx[MAXN] , lt[MAXN] , rt[MAXN] , col[MAXN] , vis[MAXN];
vector<pair<int ,int>> vp[2];
const int INF = 2e6 + 10;
struct segMin
{
    int BASE;
    vector<int> tree;
    void init(int _n )
    {
        BASE = _n;
        while(__builtin_popcount(BASE) != 1)
        {
            BASE++;
        }
        tree.assign(2*BASE , INF);
    }
    void upd(int x , int y)
    {
        tree[x + BASE] = y;
        for(int j = (x + BASE)/2 ; j >= 1; j/=2)
        {
            tree[j] = min(tree[2*j] , tree[2*j + 1]);
        }
    }
    int query(int l , int r)
    {
        if(l > r)
            return INF;
        l+=BASE;
        r+=BASE;
        if(l == r)
            return tree[l];
        int left = tree[l] , right = tree[r];
        while(l + 1 < r)
        {
            if(l % 2 == 0)
                left = min(left , tree[l + 1]);
            if(r % 2 == 1)
                right = min(tree[r - 1] , right);
            l>>=1;
            r>>=1;
        }
        return min(left , right);
    }
}sL;
struct segMax
{
    int BASE;
    vector<int> tree;
    void init(int _n )
    {
        BASE = _n;
        while(__builtin_popcount(BASE) != 1)
        {
            BASE++;
        }
        tree.assign(2*BASE , -INF);
    }
    void upd(int x , int y)
    {
        tree[x + BASE] = y;
        for(int j = (x + BASE)/2 ; j >= 1; j/=2)
        {
            tree[j] = max(tree[2*j] , tree[2*j + 1]);
        }
    }
    int query(int l , int r)
    {
        if(l > r)
            return -INF;
        l+=BASE;
        r+=BASE;
        if(l == r)
            return tree[l];
        int left = tree[l] , right = tree[r];
        while(l + 1 < r)
        {
            if(l % 2 == 0)
                left = max(left , tree[l + 1]);
            if(r % 2 == 1)
                right = max(tree[r - 1] , right);
            l>>=1;
            r>>=1;
        }
        return max(left , right);
    }
}sR;

void dfs(int x , int c)
{
    if(vis[x])
    {
        if(c != col[x])
            is_bipartite = 0;
        return ;
    }
    vp[c].pb({lt[x] , rt[x]});
    col[x] = c;
    vis[x] = 1;
    while(true)
    {
        int r = sR.query(lt[x] + 1 , rt[x] - 1);
        if(r <= rt[x])
            break;
        int i = idx[r];
        sR.upd(lt[i] , -INF);
        sL.upd(rt[i] , INF);
        dfs(i , 1 - c);
    }
    while(true)
    {
        int l = sL.query(lt[x] + 1 , rt[x] - 1);
        if(l >= lt[x])
            break;
        int i = idx[l];
        sR.upd(lt[i] , -INF);
        sL.upd(rt[i] , INF);
        dfs(i , 1 - c);
    }
}
bool check(int t)
{
    sort(vp[t].begin() , vp[t].end());
    set<int> s;
    for(auto [l , r] : vp[t])
    {
        auto it = s.lower_bound(r);
        if(it != s.begin())
        {
            it--;
            if(l < *it)
                return 0;
        }
        s.insert(r);
    }
    return 1;
}
signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>n;
    sL.init(2*n + 1);
    sR.init(2*n + 1);
    fore(i , n)
    {
        cin>>lt[i]>>rt[i];
        sL.upd(rt[i] , lt[i]);
        sR.upd(lt[i] , rt[i]);
        idx[lt[i]] = i;
        idx[rt[i]] = i;
    }
    fore(i , n)
    {
        if(!vis[i])
        {
            dfs(i , 0);
            ans = (ans * 2)%MOD;
        }
    }
    if(check(0) && check(1))
        cout<<ans<<nl;
    else
        cout<<0<<nl;
}

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