【POJ3377】Ferry Lanes 最短路

标签：poj3377   最短路   手写堆   优化   

我只是贴一下手写堆优化的dij模板，虽然，它，TLE了……****

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#define N 2001000
#define inf 0x3f3f3f3f
#define longlong int
using namespace std;
struct Katarina
{
	int v,next;
	longlong len;
}e[N<<2];
int head[N],cnt;
void add(int u,int v,longlong len)
{
	cnt++;
	e[cnt].v=v;
	e[cnt].len=len;
	e[cnt].next=head[u];
	head[u]=cnt;
}
struct Fiona
{
	longlong f;
	int v;
	bool operator < (const Fiona &a)const
	{return f<a.f;}
	bool operator >= (const Fiona &a)const
	{return f>=a.f;}
	bool operator > (const Fiona &a)const
	{return f>a.f;}
	Fiona(longlong _f,int _v):f(_f),v(_v){}
	Fiona(){}
};
struct Heap
{
	Fiona w[N];
	int cnt,crs[N];
	void init(){cnt=0;memset(crs,0,sizeof(crs));}
	void pushup(int &x){while((x>>1)&&w[x>>1]>w[x])swap(w[x>>1],w[x]),crs[w[x].v]=x,x>>=1;}
	void pushdown(int &x)
	{
		while((x<<1)<=cnt)
		{
			int son=(x<<1==cnt)?(x<<1):(w[x<<1]<w[x<<1|1]?(x<<1):(x<<1|1));
			if(w[son]>=w[x])break;
			else swap(w[x],w[son]),crs[w[x].v]=x;
			x=son;
		}
	}
	void push(Fiona X)
	{
		if(!crs[X.v])
		{
			w[++cnt]=X;
			pushup(crs[X.v]=cnt);
		}
		else
		{
			w[crs[X.v]]=X;
			pushup(crs[X.v]);
		}
	}
	Fiona top()/*add to a pop*/
	{
		Fiona ret=w[1];
		crs[w[1].v]=0;
		w[1]=w[cnt--];
		if(cnt)pushdown(crs[w[1].v]=1);
		return ret;
	}
}heap;
longlong dist[N];
bool visit[N];
int n;
longlong dij(int s,int t)
{
	int i,u,v,round;
	heap.init();
	memset(dist,0x3f,sizeof(dist));
	memset(visit,0,sizeof(visit));
	dist[s]=0;
	heap.push(Fiona(dist[s],s));
	for(round=1;round<=n;round++)
	{
		Fiona U=heap.top();
		u=U.v;
		visit[u]=1;
		for(i=head[u];i;i=e[i].next)
		{
			v=e[i].v;
			if(!visit[v]&&dist[v]>dist[u]+e[i].len)
			{
				dist[v]=dist[u]+e[i].len;
				heap.push(Fiona(dist[v],v));
			}
		}
	}
	return dist[t];
}
int main()
{
//	freopen("test.in","r",stdin);
//	freopen("1.out","w",stdout);
	int i,a,b,c,d;
	int s,t,temp;
	while(scanf("%d",&n),n)
	{
		n++;cnt=0;
		memset(head,0,sizeof(head));
		scanf("%d%d%d%d",&a,&b,&c,&d);
		s=a*n+b+1;
		t=c*n+d+1;
		for(i=1;i<n;i++)
		{
			scanf("%d",&temp);
			add(i,i+1,temp);
			add(i+1,i,temp);
		}
		for(i=1;i<=n;i++)
		{
			scanf("%d",&temp);
			add(i,i+n,temp);
			add(i+n,i,temp);
		}
		for(i=n+1,n<<=1;i<n;i++)
		{
			scanf("%d",&temp);
			add(i,i+1,temp);
			add(i+1,i,temp);
		}
		cout<<dij(s,t)<<endl;
	}
//	fclose(stdin);
//	fclose(stdout);
	return 0;
}

【POJ3377】Ferry Lanes 最短路

标签：poj3377   最短路   手写堆   优化   

原文地址：http://blog.csdn.net/vmurder/article/details/40742705