Submission #759797

#	Time	Username	Problem	Language	Result	Execution time	Memory
759797		alexander707070	Meetings (IOI18_meetings)	C++14	0 / 100	813 ms	29872 KiB

meetings

#include<bits/stdc++.h>
#define MAXN 100007
using namespace std;

struct event{
    int pos;
    int val;
    int type;

    inline friend bool operator < (event fr,event sc){
        return fr.pos<sc.pos;
    }
};

const int inf=1e9+7;

int n,h[MAXN],q,l,r,pt,pr[MAXN],nxt[MAXN],lt,rt;
long long curr;
vector< pair<int,int> > st;
vector<long long> ans;

vector<event> w;

long long calc[MAXN][21][21];

void precalc(){
    st.clear(); st.push_back({inf,0});
    for(int i=1;i<=n;i++){
        while(h[i]>=st.back().first){
            st.pop_back();
        }

        pr[i]=st.back().second;
        st.push_back({h[i],i});
        
        pt=st.size()-1; curr=0;
        for(int f=h[i];f<=20;f++){
            while(st[pt].first<=f){
                curr+=(long long) st[pt].first*(st[pt].second-st[pt-1].second);
                pt--;
            }
            for(int k=1;k<=20;k++){
                calc[i][f][k]+=curr;
            }
        }
    }

    st.clear(); st.push_back({inf,n+1});
    for(int i=n;i>=1;i--){
        while(h[i]>=st.back().first){
            st.pop_back();
        }

        nxt[i]=st.back().second;
        st.push_back({h[i],i});

        pt=st.size()-1; curr=0;
        for(int f=h[i];f<=20;f++){
            while(st[pt].first<=f){
                curr+=(long long) st[pt].first*(st[pt-1].second-st[pt].second);
                pt--;
            }
            for(int k=1;k<=20;k++){
                calc[i][k][f]+=(long long) curr-h[i];
            }
        }
    }
}

long long getmin(int l,int r,int lt,int rt){
    long long res=1e16;

    for(int i=l;i<=r;i++){
        res=min(res,calc[i][lt][rt]);
    }

    return res;
}

vector<long long> minimum_costs(vector<int> H,vector<int> L,vector<int> R){
    n=int(H.size()); q=int(L.size());

    for(int i=1;i<=n;i++){
        h[i]=H[i-1];
    }

    precalc();

    for(int i=0;i<q;i++){
        l=L[i]+1; r=R[i]+1;

        w.clear();
        for(int f=l;f<=r;f=nxt[f]){
            w.push_back({f,h[f],0});
        }
        for(int f=r;f>=l;f=pr[f]){
            w.push_back({max(pr[f]+1,l),h[f],1});
        }
        w.push_back({r+1,0,0});
        sort(w.begin(),w.end());

        curr=1e16;
        for(int f=0;f<w.size()-1;f++){
            if(w[f].type==0)lt=w[f].val;
            if(w[f].type==1)rt=w[f].val;

            curr=min(curr,(long long) getmin(w[f].pos,w[f+1].pos-1,lt-1,rt-1)+(w[f].pos-l+1)*lt+(r-w[f+1].pos+1)*rt);
        }

        ans.push_back(curr);
    }

    return ans;
}

/*
int main(){
     minimum_costs({2, 4, 3, 5}, {0, 1}, {2, 3});

     for(int i=0;i<ans.size();i++){
        cout<<ans[i]<<" ";
     }
}
*/

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:103:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<event>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |         for(int f=0;f<w.size()-1;f++){
      |                     ~^~~~~~~~~~~

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