Submission #1013733

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013733		hengliao	Fire (BOI24_fire)	C++17	34 / 100	205 ms	88896 KiB

Main

#include<bits/stdc++.h>
#include <chrono>
#include <random>
using namespace std;

#define F first
#define S second
#define pb push_back
#define vll vector<ll>
#define pll pair<ll, ll>
typedef long long ll;

const ll mxN=2e5+5;
const ll LOG=21;
const ll inf=1e18;

ll pw[LOG];

struct seg{
    ll s, e;
    seg *up[LOG];

    bool operator< (const seg &tar) const{
        if(s!=tar.s){
            return s<tar.s;
        }
        return e<tar.e;
    }

    ll bs(ll tar){
        ll re=0;
        if(e>=tar){
            return 1;
        }
        seg *cur=this;
        for(ll i=LOG-1;i>=0;i--){
            if(cur->up[i]->e<tar){
                re+=pw[i];
                cur=cur->up[i];
            }
        }
        return re+2;
    }
};

ll n, m;
vector<seg> a;
vll con;

ll getidx(ll tar){
    return lower_bound(con.begin(), con.end(), tar)-con.begin();
}

void solve(){
	cin>>n>>m;
    a.resize(n);
    for(ll i=0;i<n;i++){
        cin>>a[i].s>>a[i].e;
    }
    for(ll i=0;i<n;i++){
        if(a[i].s>a[i].e){
            a[i].e+=m;
        }
    }
    sort(a.begin(), a.end());
    for(ll i=0;i<n;i++){
        seg tep={a[i].s+m, a[i].e+m};
        tep.e=min(tep.e, 2*m);
        a.pb(tep);
    }
    for(auto &cur:a){
        con.pb(cur.s);
        con.pb(cur.e);
    }
    sort(con.begin(), con.end());
    con.erase(unique(con.begin(), con.end()), con.end());
    ll pt=0;
    seg *mx=new seg();
    mx->s=0;
    mx->e=0;
    vector<seg*> bst(con.size());
    for(ll i=0;i<con.size();i++){
        ll it=con[i];
        if(it<a[0].s) continue;
        while(pt<a.size() && a[pt].s<=it){
            if(a[pt].e>(mx->e)){
                mx=&a[pt];
            }
            pt++;
        }
        bst[i]=mx;
    }
    for(ll i=0;i<a.size();i++){
        ll id=getidx(a[i].e);
        a[i].up[0]=bst[id];
    }
    for(ll j=1;j<LOG;j++){
        for(ll i=0;i<a.size();i++){
            a[i].up[j]=a[i].up[j-1]->up[j-1];
        }
    }
    for(ll i=0;i<n;i++){
        if(a[i].up[LOG-1]->e<a[i].s+m){
            cout<<-1<<'\n';
            return;
        }
    }
    ll ans=inf;
    for(ll i=0;i<n;i++){
        ll re=a[i].bs(a[i].s+m);
        ans=min(ans, re);
    }
    cout<<ans<<'\n';
}

int main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

    pw[0]=1;
    for(ll i=1;i<LOG;i++){
        pw[i]=pw[i-1]*2;
    }

	solve();
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:82:17: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |     for(ll i=0;i<con.size();i++){
      |                ~^~~~~~~~~~~
Main.cpp:85:17: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<seg>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |         while(pt<a.size() && a[pt].s<=it){
      |               ~~^~~~~~~~~
Main.cpp:93:17: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<seg>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   93 |     for(ll i=0;i<a.size();i++){
      |                ~^~~~~~~~~
Main.cpp:98:21: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<seg>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |         for(ll i=0;i<a.size();i++){
      |                    ~^~~~~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 17
• Subtask 3: 0 / 9
• Subtask 4: 13 / 13
• Subtask 5: 21 / 21
• Subtask 6: 0 / 26