Submission #419283

#	Time	Username	Problem	Language	Result	Execution time	Memory
419283		ryansee	Event Hopping 2 (JOI21_event2)	C++14	7 / 100	153 ms	20504 KiB

event2

#include "bits/stdc++.h"
using namespace std;

#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusive
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }

using ll=long long;
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,ll>; 

long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (100006)
int n,k,p[MAXN][17],co;
pi A[MAXN];
vector<spi> v, u;
set<dpi> events;
ll solve(ll x,ll y) {
	// bsearch for last event that ends before y
	ll st=-1,en=siz(v);
	while(en-st>1) {
		ll mid=(st+en)>>1;
		if(v[mid].s.s <= y) st = mid;
		else en = mid;
	}
	if(st == -1 || v[st].s.f < x) return 0;
	ll ans = 1, i = v[st].f;
	DEC(j,16,0) if(p[i][j] != -1 && A[p[i][j]].f >= x) i = p[i][j], ans += 1<<j;
	return ans;
}
int main() {
	FAST
	cin>>n>>k;
	FOR(i,1,n)cin>>A[i].f>>A[i].s, v.eb(i, A[i]);
	sort(all(v), [](spi x,spi y){return pi(x.s.f,-x.s.s)<pi(y.s.f,-y.s.s);});
	DEC(i,n-1,0) if(u.empty() || u.back().s.s > v[i].s.s) {
		u.eb(v[i]);
	}
	v.clear(); while(u.size()) v.eb(u.back()), u.pop_back();
	deque<int> dq;
	for(auto i:v) {
		if(dq.empty()) {
			p[i.f][0] = -1;
		} else {
			while(dq.size() > 1 && A[dq[1]].s <= i.s.f) dq.pop_front();
			p[i.f][0] = dq[0];
		}
		dq.eb(i.f);
	}
	FOR(j,1,16) FOR(i,1,n) if(p[i][j-1] != -1) p[i][j]=p[p[i][j-1]][j-1]; else p[i][j] = -1;
	events.ins(dpi(pi(0, 1), -1)), events.ins(dpi(pi(1e9, int(1e9) + 1), -1));
	co = solve(1, 1e9);
	FOR(i,1,n) {
		auto it = prev(events.upper_bound(dpi(pi(A[i].f, LLINF),LLINF)));
		if(it->f.s > A[i].f) continue;
		++ it;
		if(it->f.f < A[i].s) continue;
		int tmp = solve(prev(it)->f.s, it->f.f);
		int wow = solve(prev(it)->f.s, A[i].f) + solve(A[i].s, it->f.f) + 1;
		if(co - tmp + wow < k) continue;
		co += wow - tmp;
		events.ins(dpi(A[i], i));
		if(events.size() == k+2) break;
	}
	if(events.size() != k+2) {
		cout<<"-1\n";
	} else {
		vector<int> ind;
		for(auto i:events) if(i.s != -1) ind.eb(i.s);
		sort(all(ind));
		for(auto i:ind) cout<<i<<'\n';
	}
}

Compilation message (stderr)

event2.cpp: In function 'int main()':
event2.cpp:78:20: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   78 |   if(events.size() == k+2) break;
      |      ~~~~~~~~~~~~~~^~~~~~
event2.cpp:80:19: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<std::pair<long long int, long long int>, long long int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   80 |  if(events.size() != k+2) {
      |     ~~~~~~~~~~~~~~^~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 1
• Subtask 3: 0 / 31
• Subtask 4: 0 / 61