Submission #1098802

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098802		azberjibiou	Meetings (IOI18_meetings)	C++17	19 / 100	5556 ms	12352 KiB

meetings

#include "meetings.h"
#include <bits/stdc++.h>
#define all(v) v.begin(), v.end()
#define pb push_back
#define lb lower_bound
#define gibon ios::sync_with_stdio(false); cin.tie(0);
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
typedef long long ll;
using namespace std;
const int mxN=750005;
const int mxM=2200005;
const int mxK=61;
const int MOD=1e9+7;
const ll INF=1e18;
int N, Q;
ll H[mxN];
pii qry[mxN];
ll l[mxN], r[mxN];
ll ldp[mxN], rdp[mxN]; // ldp[i] : [l[i]+1, i]에서 시작점을 선택해서 [l[i]+1, i-1]에 대한 최소 비용
ll rval[mxN], lval[mxN];
ll ans[mxN];
void init(vector <int> h, vector <int> L, vector <int> R){
    N=h.size();
    for(int i=0;i<N;i++) H[i]=h[i];
    Q=L.size();
    for(int i=0;i<Q;i++) qry[i]=pii(L[i], R[i]);
}
/*
void input(){
    cin >> N >> Q;
    for(int i=0;i<N;i++) cin >> H[i];
    for(int i=0;i<Q;i++) cin >> qry[i].fi >> qry[i].se;
}
*/
void make_cartesian_tree(){ // 두 산의 높이가 같으면 오른쪽에 있는 산의 높이가 더 높다
    stack <int> stk;
    for(int i=0;i<N;i++){
        while(stk.size() && H[stk.top()]<=H[i]) stk.pop();
        if(stk.size()) l[i]=stk.top();
        else l[i]=-1;
        stk.push(i);
    }
    while(stk.size()) stk.pop();
    for(int i=N-1;i>=0;i--){
        while(stk.size() && H[stk.top()]<H[i]) stk.pop();
        if(stk.size()) r[i]=stk.top();
        else r[i]=-1;
        stk.push(i);
    }
}
void make_dp(){
    //길이 2짜리 segment의 비용은 0이다
    vector <pii> v;
    for(int i=0;i<N;i++){
        if(l[i]!=-1 && r[i]!=-1) v.emplace_back(max(i-l[i], r[i]-i), i);
    }
    sort(all(v));
    for(auto [d, i] : v){
        if(H[l[i]]<=H[r[i]]){
            int now=l[i];
            rdp[now]=min(rdp[i]+(i-l[i])*H[i], ldp[i]+(r[i]-i)*H[i]);
        }
        else{
            int now=r[i];
            ldp[now]=min(rdp[i]+(i-l[i])*H[i], ldp[i]+(r[i]-i)*H[i]);
        }
    }
}
void make_lrval(){
    for(int i=N-1;i>=0;i--){
        if(r[i]==-1) rval[i]=(N-i)*H[i];
        else rval[i]=(r[i]-i)*H[i]+rval[r[i]];
    }
    for(int i=0;i<N;i++){
        if(l[i]==-1) lval[i]=(i+1)*H[i];
        else lval[i]=(i-l[i])*H[i]+lval[l[i]];
    }
}
void solv_query(){
    for(int i=0;i<Q;i++) ans[i]=INF;
    for(int i=0;i<Q;i++){
        auto [s, e]=qry[i];
        int now=s;
        int hmax=now;
        while(r[hmax]!=-1 && r[hmax]<=e) hmax=r[hmax];
        while(r[now]!=-1 && r[now]<=e){
            ans[i]=min(ans[i], rdp[now]+(now-s+1)*H[now]+rval[r[now]]-rval[hmax]+(e-hmax+1)*H[hmax]);
            now=r[now];
        }
        ans[i]=min(ans[i], H[now]*(e-s+1));
        now=e;
        while(l[now]!=-1 && l[now]>=s){
            ans[i]=min(ans[i], ldp[now]+(e-now+1)*H[now]+lval[l[now]]-lval[hmax]+(hmax-s+1)*H[hmax]);
            now=l[now];
        }
    }
    //for(int i=0;i<Q;i++) cout << ans[i] << '\n';
}
void solv(){
    make_cartesian_tree();
    make_dp();
    //for(int i=0;i<N;i++) printf("l[%d]=%d, r[%d]=%d\n", i, l[i], i, r[i]);
    make_lrval();
    //for(int i=0;i<N;i++) printf("l/rval[%d]=%lld %lld\n", i, lval[i], rval[i]);
    solv_query();
}
vector<ll> minimum_costs(vector<int> h, vector<int> L, vector<int> R) {
    init(h, L, R);
    solv();
    vector <ll> C(Q);
    for(int j=0;j<Q;j++) C[j]=ans[j];
    return C;
}
/*
int main()
{
    gibon
    input();
    solv();   
}
*/

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