제출 #205764

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
205764		nafis_shifat	Evacuation plan (IZhO18_plan)	C++14	100 / 100	1763 ms	63168 KiB

plan

#include<bits/stdc++.h>
#define pii pair<int,int>
#define f first
#define s second
#define ll long long
using namespace std;
const int mxn=1e5+10;
const int inf=1e9+10;

vector<int> adj[mxn];
vector<int> cost[mxn];

int dst[mxn];
vector<int> g;

void dijkstra()
{
	priority_queue<pii> pq;
	for(int i=0;i<g.size();i++)
	{
		pq.push({0,g[i]});
		dst[g[i]]=0;
	}

	int vis[mxn]={};

	while(!pq.empty())
	{
		int u=pq.top().s;		
		pq.pop();
		if(vis[u])continue;
		vis[u]=1;
		

		for(int i=0;i<adj[u].size();i++)
		{
			int v=adj[u][i];
			if(dst[u]+cost[u][i]<dst[v])
			{
				dst[v]=dst[u]+cost[u][i];
				pq.push({-dst[v],v});
			}
		}

	}

}
int col[mxn]={};
priority_queue<pair<int,pii>> edg;

vector<int> mst[mxn];
vector<int> cst[mxn];

void add(int n)
{
	for(int i=1;i<=n;i++)
	{
		for(int j=0;j<adj[i].size();j++)
		{
			int v=adj[i][j];
			if(i<v)edg.push({min(dst[i],dst[v]),{i,v}});
			
		}
	}
}

int parent[mxn];
int findrep(int u)
{
	if(parent[u]==u)return u;
	return parent[u]=findrep(parent[u]);
}
void _union(int u,int v)
{
	parent[findrep(u)]=findrep(v);
}



int pa[22][mxn];
int dp[22][mxn];
int level[mxn]={};
void dfs(int cur,int prev,int v)
{
	pa[0][cur]=prev;
	dp[0][cur]=v;
	level[cur]=level[prev]+1;

	for(int i=0;i<mst[cur].size();i++)
	{
		if(mst[cur][i]==prev)continue;

		dfs(mst[cur][i],cur,cst[cur][i]);
	}
}

void init_lca(int n)
{
	for(int i=1;i<18;i++)
	{
		for(int j=1;j<=n;j++)
		{
			if(pa[i-1][j]!=-1)
			{
				pa[i][j]=pa[i-1][pa[i-1][j]];
				dp[i][j]=min(dp[i-1][j],dp[i-1][pa[i-1][j]]);
			}
		}
	}
}


int findlca(int u,int v)
{
	if(level[u]<level[v])swap(u,v);
	int diff=level[u]-level[v];
	for(int i=0;i<18;i++)
		if((diff>>i)&1)u=pa[i][u];
	if(u==v)return u;
	for(int i=17;i>=0;i--)
	{
		if(pa[i][u]!=pa[i][v])
		{
			u=pa[i][u];
			v=pa[i][v];
		}
	}
	return pa[0][u];
}
int getmin(int u,int v)
{
	int ans=inf;
	if(level[u]<level[v])swap(u,v);
	int diff=level[u]-level[v];
	for(int i=0;i<18;i++)
	{
		if((diff>>i)&1)
		{
			ans=min(ans,dp[i][u]);
			u=pa[i][u];
		}
	}
	return ans;

}

int main()
{
	for(int i=1;i<mxn;i++)parent[i]=i;
	int n,m;
	cin>>n>>m;

	for(int i=0;i<m;i++)
	{
		int u,v,c;
		cin>>u>>v>>c;
		adj[u].push_back(v);
		adj[v].push_back(u);
		cost[u].push_back(c);
		cost[v].push_back(c);
		dst[u]=dst[v]=inf;
	}
	int k;
	cin>>k;
	for(int i=0;i<k;i++)
	{
		int t;
		cin>>t;
		g.push_back(t);
	}

	dijkstra();
	
//	cout<<dst[2]<<endl;
	add(n);
	while(!edg.empty())
	{
		int w=edg.top().f;
		int u=edg.top().s.f;
		int v=edg.top().s.s;
		edg.pop();

		if(findrep(u)==findrep(v))continue;
		_union(u,v);
		mst[u].push_back(v);
		mst[v].push_back(u);
		cst[u].push_back(w);
		cst[v].push_back(w);
	}
	

	dfs(1,0,dst[1]);
	init_lca(n);

	int q;
	cin>>q;
	while(q--)
	{
		int u,v;
		cin>>u>>v;
		int lca=findlca(u,v);

		int ans=min(getmin(u,lca),getmin(v,lca));
		//cout<<lca<<endl;
		
		ans=min(ans,dst[u]);
		ans=min(ans,dst[v]);
		ans=min(ans,dst[lca]);
		cout<<ans<<endl;

	}













	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

plan.cpp: In function 'void dijkstra()':
plan.cpp:19:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g.size();i++)
              ~^~~~~~~~~
plan.cpp:35:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<adj[u].size();i++)
               ~^~~~~~~~~~~~~~
plan.cpp: In function 'void add(int)':
plan.cpp:58:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<adj[i].size();j++)
               ~^~~~~~~~~~~~~~
plan.cpp: In function 'void dfs(int, int, int)':
plan.cpp:89:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<mst[cur].size();i++)
              ~^~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46