Submission #274857

#	Time	Username	Problem	Language	Result	Execution time	Memory
274857		arnold518	Teams (CEOI11_tea)	C++14	80 / 100	577 ms	151544 KiB

tea

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
const int MAXN = 1e6;
const int INF = 987654321;

struct dequeue
{
	int st;
	vector<int> V;
	dequeue() : st(0) {} 
	bool empty() { return st==V.size(); }
	void push_back(int x) { V.push_back(x); }
	void push_front(int x) { V[--st]=x; }
	void pop_back() { V.pop_back(); }
	void pop_front() { st++; }
	int front() { return V[st]; }
	int back() { return V.back(); }
};

int N;
pii B[MAXN+10];
int dp1[MAXN+10], dp2[MAXN+10];
int pmax[MAXN+10];
dequeue DQ[MAXN+10];
int memo[MAXN+10]; 
vector<int> V[MAXN+10];

int main()
{
	scanf("%d", &N);
	for(int i=1; i<=N; i++) scanf("%d", &B[i].first), B[i].second=i;
	//for(int i=1; i<=N; i++) A[i]=rand()%(N/2)+1;
	sort(B+1, B+N+1);
 
	for(int i=1; i<=N; i++)
	{
		dp1[i]=-INF;
		if(i-B[i].first>=0)
		{
			dp1[i]=pmax[i-B[i].first]+1;
			V[i-B[i].first].push_back(i);
		}
		pmax[i]=max(pmax[i-1], dp1[i]);
	}

	for(int i=0; i<=N; i++)
	{
		if(dp1[i]!=-INF)
		{
			while(!DQ[dp1[i]].empty() && dp2[DQ[dp1[i]].back()]>=dp2[i]) DQ[dp1[i]].pop_back();
			DQ[dp1[i]].push_back(i);
		}
		for(auto it : V[i])
		{
			int p=pmax[i];
			int val=-1;
			while(!DQ[p].empty() && dp2[DQ[p].front()]<=it-DQ[p].front())
			{
				val=DQ[p].front();
				DQ[p].pop_front();
			}
			if(val!=-1 && (DQ[p].empty() || max(it-val, dp2[val])<dp2[DQ[p].front()])) DQ[p].push_front(val);
			dp2[it]=max(it-DQ[p].front(), dp2[DQ[p].front()]);
			memo[it]=DQ[p].front();
		}
	}

	printf("%d\n", dp1[N]);
	int now=N; int cnt=0;
	while(now)
	{
		printf("%d ", now-memo[now]); cnt++;
		for(int i=now; i>memo[now]; i--) printf("%d ", B[i].second);
		printf("\n"); now=memo[now];
	}
	assert(cnt==dp1[N]);
}

Compilation message (stderr)

tea.cpp: In member function 'bool dequeue::empty()':
tea.cpp:16:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  bool empty() { return st==V.size(); }
      |                        ~~^~~~~~~~~~
tea.cpp: In function 'int main()':
tea.cpp:35:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |  scanf("%d", &N);
      |  ~~~~~^~~~~~~~~~
tea.cpp:36:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   36 |  for(int i=1; i<=N; i++) scanf("%d", &B[i].first), B[i].second=i;
      |                          ~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10