BZOJ2200: [Usaco2011 Jan]道路和航线

  1 #include<stdio.h>
  2 #include<string.h>
  3 #include<algorithm>
  4 #include<math.h>
  5 //#include<iostream>
  6 #include<queue>
  7 using namespace std;
  8 
  9 int n,m1,m2,s;
 10 #define maxn 25011
 11 #define maxm 100011
 12 const int inf=0x3f3f3f3f;
 13 struct Edge{int to,next,v;};
 14 struct qnode
 15 {
 16     int v,id;
 17     bool operator < (const qnode &b) const {return v<b.v;}
 18     bool operator > (const qnode &b) const {return v>b.v;}
 19 };
 20 int ufs[maxn];
 21 void ufsclear(int n)
 22 {
 23     for (int i=1;i<=n;i++) ufs[i]=i;
 24 }
 25 int find(int x) {return x==ufs[x]?x:(ufs[x]=find(ufs[x]));}
 26 void Union(int x,int y)
 27 {
 28     x=find(x),y=find(y);
 29     if (x==y) return;
 30     ufs[x]=y;
 31 }
 32 struct Graph
 33 {
 34     Edge road[maxm],fly[maxm];
 35     int froad[maxn],ffly[maxn],lr,lf;
 36     Graph()
 37     {
 38         memset(froad,0,sizeof(froad));
 39         memset(ffly,0,sizeof(ffly));
 40         lr=lf=2;
 41     }
 42     void in(Edge *edge,int *first,int &le,int x,int y,int v)
 43     {
 44         Edge &e=edge[le];
 45         e.to=y;e.v=v;
 46         e.next=first[x];
 47         first[x]=le++;
 48     }
 49     void insert(Edge *edge,int *first,int &le,int x,int y,int v)
 50     {
 51         in(edge,first,le,x,y,v);
 52         in(edge,first,le,y,x,v);
 53     }
 54     void in(int x,int y,int v) {in(fly,ffly,lf,x,y,v);}
 55     void insert(int x,int y,int v) {insert(road,froad,lr,x,y,v);}
 56     int deg[maxn];
 57     int que[maxn],head,tail;bool vis[maxn];
 58     void bfs()
 59     {
 60         que[head=(tail=1)-1]=s;
 61         vis[s]=1;
 62         memset(deg,0,sizeof(deg));
 63         while (head!=tail)
 64         {
 65             const int now=que[head++];
 66             for (int i=froad[now];i;i=road[i].next)
 67             {
 68                 Edge &e=road[i];
 69                 if (!vis[e.to]) vis[e.to]=1,que[tail++]=e.to;
 70             }
 71             for (int i=ffly[now];i;i=fly[i].next)
 72             {
 73                 Edge &e=fly[i];
 74                 deg[find(e.to)]++;
 75                 if (!vis[e.to]) vis[e.to]=1,que[tail++]=e.to;
 76             }
 77         }
 78     }
 79     Edge play[maxn];
 80     int fplay[maxn],lp;
 81     int dis[maxn];
 82     void inplay(int x,int y)
 83     {
 84         play[lp].to=y;
 85         play[lp].next=fplay[x];
 86         fplay[x]=lp++;
 87     }
 88     void dijkstra(int x)
 89     {
 90         priority_queue<qnode,vector<qnode>,greater<qnode> > q;
 91         for (int i=fplay[x];i;i=play[i].next)
 92         {
 93             Edge &e=play[i];
 94             q.push((qnode){dis[e.to],e.to});
 95             vis[e.to]=0;
 96         }
 97         while (!q.empty())
 98         {
 99             const int now=q.top().id,d=q.top().v;q.pop();
100             if (vis[now]) continue;
101             vis[now]=1;
102             for (int i=froad[now];i;i=road[i].next)
103             {
104                 Edge &e=road[i];
105                 if (dis[e.to]>d+e.v)
106                 {
107                     dis[e.to]=d+e.v;
108                     q.push((qnode){dis[e.to],e.to});
109                 }
110             }
111             for (int i=ffly[now];i;i=fly[i].next)
112             {
113                 Edge &e=fly[i];
114                 if (dis[e.to]>d+e.v)
115                 {
116                     dis[e.to]=d+e.v;
117                     if (!vis[e.to])
118                     {
119                         vis[e.to]=1;
120                         inplay(find(e.to),e.to);
121                     }
122                 }
123                 deg[find(e.to)]--;
124                 if (!deg[ufs[e.to]]) que[tail++]=ufs[e.to];
125             }
126         }
127     }
128     void solve()
129     {
130         bfs();
131         for (int i=1;i<=n;i++) dis[i]=inf;dis[s]=0;
132         memset(fplay,0,sizeof(fplay));lp=2;
133         que[head=(tail=1)-1]=find(s);
134         inplay(ufs[s],s);
135         memset(vis,0,sizeof(vis));
136         while (head!=tail)
137         {
138             const int now=que[head++];
139             dijkstra(now);
140         }
141         for (int i=1;i<=n;i++)
142             printf(dis[i]==inf?"NO PATH\n":"%d\n",dis[i]);
143     }
144 }g;
145 int x,y,v;
146 int main()
147 {
148     scanf("%d%d%d%d",&n,&m1,&m2,&s);
149     ufsclear(n);
150     for (int i=1;i<=m1;i++)
151     {
152         scanf("%d%d%d",&x,&y,&v);
153         g.insert(x,y,v);
154         Union(x,y);
155     }
156     for (int i=1;i<=m2;i++)
157     {
158         scanf("%d%d%d",&x,&y,&v);
159         g.in(x,y,v);
160     }
161     g.solve();
162     return 0;
163 }