Submission #369276

#	Time	Username	Problem	Language	Result	Execution time	Memory
369276		Berted	Feast (NOI19_feast)	C++14	100 / 100	261 ms	15728 KiB

feast

#include <iostream>
#include <queue>
#include <set>
#define ll long long
#define pii pair<int,int>
#define fst first
#define snd second
#define ppp pair<pair<ll,int>,pii>
using namespace std;
int n,k,l=-1;ll ar[300001]={},to=0;set<pii> s;
priority_queue<ppp> pq;
int main()
{
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>n>>k;
	for (int i=1;i<=n;i++) 
	{
		cin>>ar[i];
		if (ar[i]>=0)
		{
			if (l==-1) {l = i;}
		}
		else
		{
			if (l!=-1) {to+=ar[i-1] - ar[l-1];s.insert({l,i-1});l=-1;}
		}
		ar[i] += ar[i-1];
	}
	if (l!=-1) {s.insert({l,n});to+=ar[n] - ar[l-1];}
	l = -1;
	for (auto dt:s)
	{
		pq.push({{-(ar[dt.snd] - ar[dt.fst-1]),0},{dt.fst,dt.snd}});
		if (l!=-1)
		{
			pq.push({{ar[dt.fst-1] - ar[l],1},{l+1,dt.fst-1}});
		}
		l = dt.snd;
	}
	while (s.size()>k)
	{
		while (pq.size())
		{
			if (pq.top().fst.snd)
			{
				auto it = s.lower_bound({pq.top().snd.snd,pq.top().snd.snd});
				pii dt = {-1,-1},dt2 = {-1,-1};
				if (it!=s.begin()) {dt2 = *prev(it);}
				if (it!=s.end()) {dt = *it;}
				if (make_pair(dt2.snd+1,dt.fst-1)!=pq.top().snd) {pq.pop();}
				else {break;}
			}
			else
			{
				auto it = s.lower_bound({pq.top().snd.fst,pq.top().snd.snd});
				pii dt = {-1,-1};
				if (it!=s.end()) {dt = *it;}
				if (dt!=pq.top().snd) {pq.pop();}
				else {break;}
			}
		}
		to += pq.top().fst.fst;
		if (pq.top().fst.snd)
		{
			auto it = s.lower_bound(pq.top().snd);
			int l=prev(it)->fst,r=it->snd;
			s.erase(prev(it));s.erase(it);pq.pop();
			s.insert({l,r});
			pq.push({{-(ar[r] - ar[l-1]),0},{l,r}});
		}
		else
		{
			auto it = s.lower_bound(pq.top().snd);
			int l=pq.top().snd.fst,r=pq.top().snd.snd;
			if (next(it)!=s.end()) {r = next(it)->fst-1;}
			if (it!=s.begin()) {l = prev(it)->snd+1;}
			s.erase(pq.top().snd);pq.pop();
			pq.push({{ar[r] - ar[l-1],1},{l,r}});
		}
	}
	cout<<to<<"\n";
	return 0;
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:40:17: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   40 |  while (s.size()>k)
      |         ~~~~~~~~^~

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29