BZOJ3073 PA2011Journeys（线段树+bfs）

　　线段树优化建图裸题。建两棵线段树，一棵表示入一棵表示出。对题中所给的边新建一个虚拟点，将两段区间拆成线段树上对应区间，出线段树中对应区间所表示的点向虚拟点连边权0的边，虚拟点向入线段树中对应区间所表示的点连边权1的边；线段树上的点之间连边权0的边（表示入的由父亲连向儿子，表示出的由儿子连向父亲），表示相同点的叶子节点（由入连向出）之间连边权0的边。01bfs即可。

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
#include<queue>
using namespace std;
#define ll long long
#define N 500010
char getc(){char c=getchar();while ((c<'A'||c>'Z')&&(c<'a'||c>'z')) c=getchar();return c;}
int gcd(int n,int m){return m==?n:gcd(m,n%m);}
int read()
{
    int x=,f=;char c=getchar();
    while (c<''||c>'') {if (c=='-') f=-;c=getchar();}
    while (c>=''&&c<='') x=(x<<)+(x<<)+(c^),c=getchar();
    return x*f;
}
int n,m,S,id[][N],root[],v[][],p[N*],d[N*],t,cnt;
struct data{int to,nxt,len;
}edge[N<<];
struct data2{int l,r;
}tree[][N<<];
deque<int> q;
void addedge(int x,int y,int z){t++;edge[t].to=y,edge[t].nxt=p[x],edge[t].len=z,p[x]=t;}
void build(int &k,int l,int r,int p)
{
    k=++cnt;
    if (l==r) {id[p][l]=k;return;}
    int mid=l+r>>;
    build(tree[p][k].l,l,mid,p);
    build(tree[p][k].r,mid+,r,p);
    if (p==) addedge(tree[p][k].l,k,),addedge(tree[p][k].r,k,);
    else addedge(k,tree[p][k].l,),addedge(k,tree[p][k].r,);
}
void find(int &k,int l,int r,int x,int y,int p)
{
    if (l==x&&r==y) {v[p][++v[p][]]=k;return;}
    int mid=l+r>>;
    if (y<=mid) find(tree[p][k].l,l,mid,x,y,p);
    else if (x>mid) find(tree[p][k].r,mid+,r,x,y,p);
    else find(tree[p][k].l,l,mid,x,mid,p),find(tree[p][k].r,mid+,r,mid+,y,p);
}
void bfs(int S)
{
    d[S]=;q.push_back(S);
    while (!q.empty())
    {
        int x=q.front();q.pop_front();
        for (int i=p[x];i;i=edge[i].nxt)
        if (d[x]+edge[i].len<d[edge[i].to])
        {
            d[edge[i].to]=d[x]+edge[i].len;
            if (edge[i].len) q.push_back(edge[i].to);
            else q.push_front(edge[i].to);
        }
    }
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("bzoj3073.in","r",stdin);
    freopen("bzoj3073.out","w",stdout);
    const char LL[]="%I64d\n";
#else
    const char LL[]="%lld\n";
#endif
    n=read(),m=read(),S=read();
    build(root[],,n,);
    build(root[],,n,);
    for (int i=;i<=m;i++)
    {
        int a=read(),b=read(),c=read(),d=read();
        v[][]=v[][]=;cnt++;
        find(root[],,n,a,b,);
        for (int x=;x<=v[][];x++) addedge(v[][x],cnt,);
        find(root[],,n,c,d,);
        for (int x=;x<=v[][];x++) addedge(cnt,v[][x],);
        v[][]=v[][]=;cnt++;
        find(root[],,n,c,d,);
        for (int x=;x<=v[][];x++) addedge(v[][x],cnt,);
        find(root[],,n,a,b,);
        for (int x=;x<=v[][];x++) addedge(cnt,v[][x],);
    }
    for (int i=;i<=n;i++) addedge(id[][i],id[][i],);
    memset(d,,sizeof(d));bfs(id[][S]);
    for (int i=;i<=n;i++) printf("%d\n",d[id[][i]]);
    return ;
}