Submission #1094088

#TimeUsernameProblemLanguageResultExecution timeMemory
1094088alexander707070Global Warming (CEOI18_glo)C++14
15 / 100
2094 ms262144 KiB
#include<bits/stdc++.h>
#define MAXN 200007
using namespace std;

const int inf=1e9;

struct ST{
	struct node{
		int l,r,val;
	};

	node tree[30*MAXN];
	int num;
	
	void init(){
		num=1;
		tree[num]={0,0,0};
	}

	void addnode(){
		num++;
		tree[num]={0,0,0};
	}

	void check(int v){
		if(tree[v].l==0){
			addnode(); tree[v].l=num;
		}

		if(tree[v].r==0){
			addnode(); tree[v].r=num;
		}
	}

	void update(int v,long long l,long long r,int pos,int val){
		if(l==r){
			tree[v].val=max(tree[v].val,val);
		}else{
			long long tt=(l+r)/2;
			check(v);

			if(pos<=tt)update(tree[v].l,l,tt,pos,val);
			else update(tree[v].r,tt+1,r,pos,val);

			tree[v].val=max(tree[tree[v].l].val,tree[tree[v].r].val);
		}
	}

	int getmax(int v,long long l,long long r,long long ll,long long rr){
		if(ll>rr or v==0)return 0;
		if(l==ll and r==rr){
			return tree[v].val;
		}else{
			long long tt=(l+r)/2;
			return max( getmax(tree[v].l,l,tt,ll,min(tt,rr)) , getmax(tree[v].r,tt+1,r,max(tt+1,ll),rr) );
		}
	}
}seg[3];

int n,a[MAXN],ans,x,b[MAXN];
int dp[MAXN][3];

int solve(int d){
	seg[0].init();
	seg[1].init();
	seg[2].init();

	int res=0;

	for(int i=1;i<=n;i++){
		dp[i][0]=seg[0].getmax(1,0,2*inf,0,a[i]-1)+1;
		dp[i][1]=max(seg[1].getmax(1,0,2*inf,0,a[i]-1)+1 , seg[0].getmax(1,0,2*inf,0,a[i]+d-1)+1);
		dp[i][2]=max(seg[2].getmax(1,0,2*inf,0,a[i]-1)+1 , seg[1].getmax(1,0,2*inf,0,a[i]-d-1)+1);

		seg[0].update(1,0,2*inf,a[i],dp[i][0]);
		seg[1].update(1,0,2*inf,a[i],dp[i][1]);
		seg[2].update(1,0,2*inf,a[i],dp[i][2]);

		res=max(res,max(dp[i][0],max(dp[i][1],dp[i][2])));
	}

	return res;
}

int sol[2000007],pos;

int main(){

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	cin>>n>>x;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=a[i];
	}

	long long l=-x,r=x,lt,rt;
	while(l+2<r){
		lt=l+(r-l+1)/3;
		rt=r-(r-l+1)/3;
 
		int ls=solve(lt);
		int rs=solve(rt);
 
		if(ls>rs)l=lt;
		else if(rs>ls)r=rt;
		else break;
	}
	
	sort(b+1,b+n+1);
	vector<int> w={0};

	for(int i=1;i<=n;i++){
		for(int f=i+1;f<=n;f++){
			if(b[i]-b[f]+1>=-x and b[i]-b[f]+1<=x){
				w.push_back(b[i]-b[f]+1);
			}else break;
		}

		for(int f=i-1;f>=1;f--){
			if(b[i]-b[f]+1>=-x and b[i]-b[f]+1<=x){
				w.push_back(b[i]-b[f]+1);
			}else break;
		}

		for(int f=i+1;f<=n;f++){
			if(b[i]-b[f]-1>=-x and b[i]-b[f]-1<=x){
				w.push_back(b[i]-b[f]-1);
			}else break;
		}

		for(int f=i-1;f>=1;f--){
			if(b[i]-b[f]-1>=-x and b[i]-b[f]-1<=x){
				w.push_back(b[i]-b[f]-1);
			}else break;
		}
	}

	for(int i=0;i<w.size();i+=max(1,int(w.size())/1000)){
		sol[i]=solve(w[i]);
		if(sol[i]>ans){
			ans=sol[i]; pos=i;
		}
	}

	for(int i=max(0,pos-500);i<=min(int(w.size())-1,pos+500);i++){
		ans=max(ans,solve(w[i]));
	}

	cout<<ans<<"\n";

    return 0;
}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:141:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  141 |  for(int i=0;i<w.size();i+=max(1,int(w.size())/1000)){
      |              ~^~~~~~~~~
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