Submission #165477

#	Time	Username	Problem	Language	Result	Execution time	Memory
165477		Segtree	Shortcut (IOI16_shortcut)	C++14	0 / 100	3 ms	376 KiB

shortcut

#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include"shortcut.h"
using namespace std;
typedef long long ll;
#define chmin(a,b) a=min(a,b)
#define chmax(a,b) a=max(a,b)
#define N 510
ll r[N],d[N],n,cost;
ll solve(ll p,ll q){
    ll x=-1e17;
    for(int i=0;i<=p;i++){
	chmax(x,r[p]-r[i]+d[i]);
    }
    ll y=-1e17;
    for(int i=q;i<n;i++){
	chmax(y,r[i]-r[q]+d[i]);
    }
    ll ans=x+y+cost;
    for(int i=p;i<=q;i++){
	chmax(ans,x+d[i]+min(r[i]-r[p],r[q]-r[i]+cost));
	chmax(ans,y+d[i]+min(r[i]-r[p]+cost,r[q]-r[i]));
    }
    vector<int> rs,ds;
    for(int i=p;i<=q;i++){
	rs.push_back(r[i]-r[p]);
	ds.push_back(d[i]);
    }
    for(int i=p;i<=q;i++){
	rs.push_back(r[i]-r[p]+cost+r[q]-r[p]);
	ds.push_back(d[i]);
    }
    ll key=cost+r[q]-r[p];
    int j=0;
    deque<pair<ll,ll> > Q;
    for(int i=0;i<=q-p;i++){
	while(!Q.empty()&&Q.front().second<i)Q.pop_front();
	for(;(rs[j]-rs[i])*2<=key;j++){
	    while(!Q.empty()&&Q.back().first<=rs[j]+ds[j]){
		Q.pop_back();
	    }
	    Q.push_back(make_pair(rs[j]+ds[j],i));
	}
	chmax(ans,Q.front().first-rs[i]+ds[i]);
    }
    //cout<<"#"<<p<<" "<<q<<" "<<ans<<endl;
    return ans;
}
ll find_shortcut(int nn,vector<int> l,vector<int> dd,int cc){
    n=nn,cost=cc;
    for(int i=0;i<n;i++)d[i]=dd[i];
    r[0]=0;
    for(int i=0;i<n-1;i++)r[i+1]=r[i]+l[i];
    ll ans=1e17;
    for(int p=0;p<n;p++)for(int q=p+1;q<n;q++){
	chmin(ans,solve(p,q));
    }
    return ans;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 14
• Subtask 3: 0 / 8
• Subtask 4: 0 / 7
• Subtask 5: 0 / 33
• Subtask 6: 0 / 22
• Subtask 7: 0 / 4
• Subtask 8: 0 / 3