Submission #94444

#	Time	Username	Problem	Language	Result	Execution time	Memory
94444		fjzzq2002	Rail (IOI14_rail)	C++14	100 / 100	99 ms	1784 KiB

rail

#include "rail.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> pii;
#define fi first
#define se second
#define pb push_back
map<pii,int> ms;
int qry(int a,int b)
{
	if(a==b) return 0;
	if(a>b) swap(a,b);
	if(ms.count(pii(a,b)))
		return ms[pii(a,b)];
	return ms[pii(a,b)]=getDistance(a,b);
}
int d1[5005],d2[5005];
void findLocation(int n, int x, int l[], int s[])
{
	l[0]=x; s[0]=1;
	if(n==1) return;
	for(int i=0;i<n;++i)
		d1[i]=qry(0,i);
	int r;
	{
	pii mi(2e9,2e9);
	for(int i=1;i<n;++i)
		mi=min(mi,pii(d1[i],i));
	r=mi.se;
	}
	l[r]=x+d1[r]; s[r]=2;
	for(int i=0;i<n;++i) d2[i]=qry(r,i);
	vector<pii> L,R;
	for(int t=1;t<n;++t) if(t!=r)
	{
		pii u(d1[t],t);
		if(d1[t]==d1[r]+d2[t])
		{
			if(d2[t]<=d1[r])
				l[t]=l[r]-d2[t], s[t]=1;
			else L.pb(u);
		}
		else R.pb(u);
	}
	sort(L.begin(),L.end());
	sort(R.begin(),R.end());
	{
	set<int> xs;
	xs.insert(l[r]);
	int g=r;
	for(auto _:R)
	{
		int t=_.se;
		int dt=(d1[g]+qry(g,t)-d1[t])/2;
		if(xs.count(l[g]-dt))
			l[t]=l[g]-qry(g,t), s[t]=1;
		else
			l[t]=l[0]+d1[t], s[t]=2,
			g=t, xs.insert(l[t]);
//		cerr<<t<<"w"<<l[t]<<" "<<s[t]<<"\n";
	}
	}
	{
	set<int> xs;
	xs.insert(l[0]);
	int g=0;
	for(auto _:L)
	{
		int t=_.se;
		int dt=(d2[g]+qry(g,t)-d2[t])/2;
		if(xs.count(l[g]+dt))
			l[t]=l[g]+qry(g,t), s[t]=2;
		else
			l[t]=l[r]-d2[t], s[t]=1,
			g=t, xs.insert(l[t]);
	}
	}
//	for(auto u:L)
//		cerr<<u.se<<",";cerr<<"L\n";
//	for(auto u:R)
//		cerr<<u.se<<",";cerr<<"R\n";
//	cerr<<0<<"w"<<r<<"\n";
}

• Subtask 1: 8 / 8
• Subtask 2: 22 / 22
• Subtask 3: 26 / 26
• Subtask 4: 44 / 44