Submission #1244878

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244878		hainam2k9	Event Hopping 2 (JOI21_event2)	C++20	100 / 100	140 ms	22444 KiB

event2

#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
#define mp make_pair
using namespace std;
const int MOD = 1e9+7, MAXN = 2e5+5;
const string NAME = "";
int n,k,nxt[MAXN][20],sum=0;
pair<int,int> p[MAXN];
vector<int> v;
set<pair<int,int>> s;
void compress(){
    vector<int> v;
    for(int i = 1; i<=n; ++i)
        v.pb(p[i].fi), v.pb(p[i].se);
    sort(v.begin(),v.end());
    for(int i = 1; i<=n; ++i)
        p[i].fi=lb(v.begin(),v.end(),p[i].fi)-v.begin()+1,
        p[i].se=lb(v.begin(),v.end(),p[i].se)-v.begin()+1;
}
int getmax(int l, int r){
    int rs=0;
    for(int i = 18; i>=0; --i)
        if(nxt[l][i]<=r) l=nxt[l][i]+1, rs|=1<<i;
    return rs;
}
pair<int,int> check(pair<int,int> p){
    int L=1, R=2*n;
    auto it = s.lb(p);
    if(it!=s.end()&&p.se>=it->fi) return {0,0};
    if(it!=s.end()) R=it->fi-1;
    if(it!=s.begin()&&prev(it)->se>=p.fi) return {0,0};
    if(it!=s.begin()) L=prev(it)->se+1;
    return {L,R};
}
int main()
{
    tt;
    if(fopen((NAME + ".INP").c_str(), "r")) fo;
    cin >> n >> k;
    for(int i = 1; i<=n; ++i)
        cin >> p[i].fi >> p[i].se, --p[i].se;
    compress();
    memset(nxt,0x3f,sizeof(nxt));
    for(int i = 1; i<=n; ++i)
        nxt[p[i].fi][0]=min(nxt[p[i].fi][0],p[i].se);
    for(int i = n*2; i>0; --i){
        nxt[i][0]=min(nxt[i][0],nxt[i+1][0]);
        for(int j = 1; j<=18; ++j)
            if(nxt[i][j-1]<n*2) nxt[i][j]=nxt[nxt[i][j-1]+1][j-1];
    }
    sum=getmax(1,2*n);
    if(sum<k) return cout << -1, 0;
    for(int i = 1; i<=n; ++i){
        if(sz(v)==k) break;
        pair<int,int> tmp=check(p[i]);
        if(tmp==mp(0,0)) continue;
        int L=tmp.fi,R=tmp.se,newsum=sum-getmax(L,R)+getmax(L,p[i].fi-1)+getmax(p[i].se+1,R)+1;
        if(newsum>=k) v.pb(i), s.ins(p[i]), sum=newsum;
    }
    for(int& x : v) cout << x << "\n";
}

Compilation message (stderr)

event2.cpp: In function 'int main()':
event2.cpp:3:19: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
event2.cpp:53:45: note: in expansion of macro 'fo'
   53 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~
event2.cpp:3:63: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    3 | #define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
      |                                                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
event2.cpp:53:45: note: in expansion of macro 'fo'
   53 |     if(fopen((NAME + ".INP").c_str(), "r")) fo;
      |                                             ^~

• Subtask 1: 7 / 7
• Subtask 2: 1 / 1
• Subtask 3: 31 / 31
• Subtask 4: 61 / 61