bzoj4152 [AMPPZ2014]The Captain

题目链接

最短路裸题

据说SPFA要T,用堆优dijkstra就好

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<queue>
 5 using namespace std;
 6 const long long int inf=10000000000000000;
 7 struct dui
 8 {
 9     long long int a;int b;
10     dui(long long int a=0,int b=0):a(a),b(b){}
11 };
12 struct dian
13 {
14     int x,y,id;
15 }a[200020];
16 int zhi[800080],next[800080],head[200020];
17 long long int v[800080],dis[200020];
18 int n,ed;
19 bool bo[200020];
20 bool operator < (const dui &aa,const dui &bb)//重载<符号 
21 {
22     return aa.a>bb.a;
23 }
24 priority_queue<dui>h;
25 bool com1(const dian &aa,const dian &bb)
26 {
27     return aa.x<bb.x;    
28 }
29 bool com2(const dian &aa,const dian &bb)
30 {
31     return aa.y<bb.y;
32 }
33 void add(int x,int y,int z)
34 {
35     next[++ed]=head[x],head[x]=ed,zhi[ed]=y,v[ed]=z;
36     next[++ed]=head[y],head[y]=ed,zhi[ed]=x,v[ed]=z;
37 }
38 void hh()
39 {
40     for(int i=2;i<=n;i++)dis[i]=inf;
41     h.push(dui(0,1));
42     while(!h.empty())
43     {
44         int x=h.top().b;h.pop();
45         if(bo[x])continue;bo[x]=1;
46         for(int i=head[x];i;i=next[i])
47             if(dis[zhi[i]]>dis[x]+v[i])
48             {
49                 dis[zhi[i]]=dis[x]+v[i];
50                 h.push(dui(dis[zhi[i]],zhi[i]));
51             }
52     }
53 }
54 int getint()
55 {
56     int ret=0,f=1;
57     char ch=getchar();
58     while(ch<'0'||ch>'9')
59     {
60         if(ch=='-')f=0;
61         ch=getchar();
62     }
63     while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar();
64     return f==0?-ret:ret;
65 }
66 int main()
67 {
68     n=getint();
69     for(int i=1;i<=n;i++)
70     {
71         a[i].x=getint(),a[i].y=getint();
72         a[i].id=i;
73     }
74     sort(a+1,a+n+1,com1);
75     for(int i=1;i<n;i++)add(a[i].id,a[i+1].id,a[i+1].x-a[i].x);
76     sort(a+1,a+n+1,com2);
77     for(int i=1;i<n;i++)add(a[i].id,a[i+1].id,a[i+1].y-a[i].y);
78     hh();
79     printf("%lld\n",dis[n]);
80     return 0;
81 }

 

posted @ 2016-01-22 16:27  HugeGun  阅读(406)  评论(0编辑  收藏  举报