Submission #115436

#	Time	Username	Problem	Language	Result	Execution time	Memory
115436		dsjong	Meetings (IOI18_meetings)	C++14	17 / 100	165 ms	196508 KiB

meetings

#include "meetings.h"
#include <bits/stdc++.h>
using namespace std;
long long rsq[5005][5005];
int cnt[100005];
int idx[100005];
vector<int>highs;
vector<int>nhighs;
int st[100005][20];
int query(int l,int r){
	if(l>r) return 0;
	int m=log2(r-l+1);
	//cout<<l<<" "<<r<<": "<<max(st[l][m],st[r-(1<<m)+1][m])<<endl;
	return max(st[l][m],st[r-(1<<m)+1][m]);
}
vector<long long> minimum_costs(vector<int> H, vector<int> L, vector<int> R){
	vector<long long>ret;
	int N=H.size();
	if(N<=2){
		memset(rsq,0,sizeof rsq);
		for(int i=0;i<N;i++){
			int maxi=H[i];
			rsq[i][i]=H[i];
			for(int j=i-1;j>=0;j--){
				maxi=max(maxi,H[j]);
				rsq[i][j]=rsq[i][j+1]+maxi;
			}
			maxi=H[i];
			for(int j=i+1;j<N;j++){
				maxi=max(maxi,H[j]);
				rsq[i][j]=rsq[i][j-1]+maxi;
			}
		}
		for(int q=0;q<L.size();q++){
			int l=L[q],r=R[q];
			long long res=LONG_LONG_MAX;
			for(int i=l;i<=r;i++){
				res=min(res,rsq[i][l]+rsq[i][r]-H[i]);
			}
			ret.push_back(res);
		}
	}
	else{
		int last=-1;
		cnt[0]=0;
		for(int i=0;i<N;i++){
			if(i>0) cnt[i]=cnt[i-1];
			if(H[i]==2){
				idx[i]=highs.size();
				cnt[i]++;
				highs.push_back(i);
				nhighs.push_back(-i);
			}
		}
		highs.push_back(N);
		int M=cnt[N-1];
		for(int i=0;i<M;i++){
			st[i][0]=highs[i+1]-highs[i];
		}
		for(int j=1;j<20;j++){
			for(int i=0;i<=M-(1<<j);i++){
				st[i][j]=max(st[i][j-1],st[i+(1<<(j-1))][j-1]);
			}
		}
		for(int q=0;q<L.size();q++){
			int l=L[q],r=R[q];
			if(cnt[r]-cnt[l]+(int)(H[l]==2)==0){
				ret.push_back(r-l+1);
			}
			else{
				int l1=*lower_bound(highs.begin(),highs.end(),l);
				int l2=*lower_bound(nhighs.rbegin(),nhighs.rend(),-r);
				l2*=-1;
				int ans=max(l1-l,r-l2);
				if(l1!=l2){
					int idx1=idx[l1],idx2=idx[l2]-1;
					ans=max(query(idx1,idx2)-1,ans);
				}
				ret.push_back(2*(r-l+1)-ans);
			}
			hell:;
		}
	}
	return ret;
}

Compilation message (stderr)

meetings.cpp: In function 'std::vector<long long int> minimum_costs(std::vector<int>, std::vector<int>, std::vector<int>)':
meetings.cpp:34:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int q=0;q<L.size();q++){
               ~^~~~~~~~~
meetings.cpp:65:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int q=0;q<L.size();q++){
               ~^~~~~~~~~
meetings.cpp:44:7: warning: unused variable 'last' [-Wunused-variable]
   int last=-1;
       ^~~~
meetings.cpp:81:4: warning: label 'hell' defined but not used [-Wunused-label]
    hell:;
    ^~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 15
• Subtask 3: 17 / 17
• Subtask 4: 0 / 24
• Subtask 5: 0 / 40