Submission #598593

#	Time	Username	Problem	Language	Result	Execution time	Memory
598593		yutabi	Sky Walking (IOI19_walk)	C++14	24 / 100	2548 ms	1048576 KiB

walk

#include "walk.h"


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


#define INF 1000000000000000007
#define pb push_back


typedef long long ll;
typedef pair <ll,ll> ii;





vector <vector <ii> > graph;

vector <ll> res;
priority_queue <ii> pq;
vector <bool> v;


long long min_distance(std::vector<int> x, std::vector<int> h, std::vector<int> l, std::vector<int> r, std::vector<int> y, int s, int g)
{
	ll n=x.size();
	ll m=l.size();

	vector <ii> last_added(n,ii(-1,-1));

	ll k=0;

	vector <ii> build;
	vector <pair <ll,ii> > sky;

	for(ll i=0;i<n;i++)
	{
		build.pb(ii(h[i],i));
	}

	for(ll i=0;i<m;i++)
	{
		sky.pb(make_pair(y[i],ii(l[i],r[i])));
	}

	sort(build.begin(),build.end());
	sort(sky.rbegin(),sky.rend());

	set <ll> builds;

	for(ll i=0;i<m;i++)
	{
		while(build.size() && build.back().first>=sky[i].first)
		{
			builds.insert(build.back().second);

			build.pop_back();
		}

		auto it=builds.lower_bound(sky[i].second.first);

		ll last=*it;

		ll height=sky[i].first;

		graph.pb({});
		res.pb(-1);
		v.pb(0);

		if(last_added[last].first!=-1)
		{
			graph[last_added[last].first].pb(ii(k,last_added[last].second-height));
			graph[k].pb(ii(last_added[last].first,last_added[last].second-height));
		}

		last_added[last]=ii(k,height);

		k++;






		it++;

		while(it!=builds.end() && *it<=sky[i].second.second)
		{
			ll curr=*it;

			graph.pb({});
			res.pb(-1);
			v.pb(0);

			graph[k-1].pb(ii(k,x[curr]-x[last]));
			graph[k].pb(ii(k-1,x[curr]-x[last]));

			if(last_added[curr].first!=-1)
			{
				graph[last_added[curr].first].pb(ii(k,last_added[curr].second-height));
				graph[k].pb(ii(last_added[curr].first,last_added[curr].second-height));
			}

			last_added[curr]=ii(k,height);

			k++;

			last=curr;

			it++;
		}
	}

	ll start_index;
	ll end_index;

	for(ll i=0;i<n;i++)
	{
		graph.pb({});
		res.pb(-1);
		v.pb(0);

		if(last_added[i].first!=-1)
		{
			graph[last_added[i].first].pb(ii(k,last_added[i].second-0));
			graph[k].pb(ii(last_added[i].first,last_added[i].second-0));
		}

		if(s==i)
		{
			start_index=k;
		}

		if(g==i)
		{
			end_index=k;
		}

		k++;
	}

	pq.push(ii(0,start_index));

	while(pq.size())
	{
		int index=pq.top().second;
		ll dist=-pq.top().first;

		pq.pop();

		if(v[index])
		{
			continue;
		}

		res[index]=dist;

		v[index]=1;

		for(int i=0;i<graph[index].size();i++)
		{
			if(v[graph[index][i].first]==0)
			{
				pq.push(ii(-(dist+graph[index][i].second),graph[index][i].first));
			}
		}
	}

	
	return res[end_index];
}

Compilation message (stderr)

walk.cpp: In function 'long long int min_distance(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, int, int)':
walk.cpp:162:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  162 |   for(int i=0;i<graph[index].size();i++)
      |               ~^~~~~~~~~~~~~~~~~~~~
walk.cpp:172:22: warning: 'end_index' may be used uninitialized in this function [-Wmaybe-uninitialized]
  172 |  return res[end_index];
      |                      ^

• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 18
• Subtask 5: 0 / 43