bzoj4152: [AMPPZ2014]The Captain

dij在这种稀疏图果然不够优秀啊。只是学了一发。

#include<cstdio>
#include<iostream>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<queue>
using namespace std;

struct node
{
int x,y,d,next;
}a[810000];int len,last[210000];
void ins(int x,int y,int d)
{
len++;
a[len].x=x;a[len].y=y;a[len].d=d;
a[len].next=last[x];last[x]=len;
}

struct point
{
int x,y,id;
}p[210000];
bool cmp1(point p1,point p2){return p1.x<p2.x;}
bool cmp2(point p1,point p2){return p1.y<p2.y;}

int d[210000];
struct dij
{
int x;
friend bool operator <(dij n1,dij n2){return d[n1.x]>d[n2.x];}
};priority_queue<dij>q;
bool v[210000];

int main()
{
int n;
scanf("%d",&n);
for(int i=1;i<=n;i++)
scanf("%d%d",&p[i].x,&p[i].y),p[i].id=i;

len=0;memset(last,0,sizeof(last));
sort(p+1,p+n+1,cmp1);
for(int i=1;i<n;i++)
ins(p[i].id,p[i+1].id,p[i+1].x-p[i].x),
ins(p[i+1].id,p[i].id,p[i+1].x-p[i].x);
sort(p+1,p+n+1,cmp2);
for(int i=1;i<n;i++)
ins(p[i].id,p[i+1].id,p[i+1].y-p[i].y),
ins(p[i+1].id,p[i].id,p[i+1].y-p[i].y);

memset(d,63,sizeof(d));d[1]=0;
memset(v,false,sizeof(v));v[1]=true;
dij tt;tt.x=1;q.push(tt);
while(q.empty()==false)
{
int x=q.top().x;q.pop();
for(int k=last[x];k;k=a[k].next)
{
int y=a[k].y;
if(d[y]>d[x]+a[k].d)
{
d[y]=d[x]+a[k].d;
if(v[y]==false)
{
v[y]=true;
tt.x=y;q.push(tt);
}
}
}
v[x]=false;
}
printf("%d\n",d[n]);
return 0;
}

pain and happy in the cruel world.
posted @ 2018-04-16 19:45  AKCqhzdy  阅读(116)  评论(0编辑  收藏  举报