hdu1542 线段树+扫描线+离散化

仅仅想说题目给的欲实际不服     还是这类型的水题吧   建议看之前我写的那个

#include<stdio.h>

#include<string.h>

#include<algorithm>

#include<iostream>

using namespace std;

#define LL(x) (x<<1)

#define RR(x) ((x<<1)|1)





int n;

struct node

{

double y;

int x1,x2;

int flash;

}A[31000];

struct Node

{

int ii;

double x;

}change[35000];

int cmp1(Node a,Node b)

{

return a.x<b.x;

}

int cmp2(node a,node b)

{

return a.y<b.y;

}

int num[80000];

double map[31000];

int update(int L,int R,int left,int right,int k,int mark)

{

int mid=(L+R)/2;

if(L==left&&right==R)

{

if(num[mark]!=-1)

{

num[mark]+=k;

return 0;

}

update(L,mid,L,mid,k,LL(mark));

update(mid,R,mid,R,k,RR(mark));

if(num[LL(mark)]==num[RR(mark)]) num[mark]=num[LL(mark)];

else num[mark]=-1;

}

else

{

if(num[mark]>=0)

{

num[LL(mark)]=num[RR(mark)]=num[mark];

}

if(right<=mid)

{

update(L,mid,left,right,k,LL(mark));

}

else if(left>=mid)

{

update(mid,R,left,right,k,RR(mark));

}

else

{

update(L,mid,left,mid,k,LL(mark));

update(mid,R,mid,right,k,RR(mark));

}

if(num[LL(mark)]==num[RR(mark)]) num[mark]=num[LL(mark)];

else num[mark]=-1;

}

return 0;

}

double find(int L,int R,int mark)

{

double Long=0;

if(num[mark]>=1)

{

Long+=map[R]-map[L];

return Long;

}

if(num[mark]==0) return 0;

int mid=(L+R)/2;

Long+=find(L,mid,LL(mark))+find(mid,R,RR(mark));

return Long;


}

int main()

{

int i,j,d=1;

double x1,y1,x2,y2;

while(~scanf("%d",&n),n)

{

n*=2;

//j=0;

memset(A,0,sizeof(A));

memset(map,0,sizeof(map));

memset(change,0,sizeof(change));

for(i=1;i<=n;i+=2)

{

scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);

A[i].y=y1;

A[i].flash=1;

A[i+1].y=y2;

A[i+1].flash=-1;

change[i].x=x1;

change[i+1].ii=change[i].ii=i;

change[i+1].x=x2;

} 

int leap[10000];

memset(leap,0,sizeof(leap));

sort(change+1,change+1+n,cmp1);

int j=0;

double k=-1;

for(i=1;i<=n;i++)

{

if(change[i].x!=k)

{

k=change[i].x;

++j;

map[j]=change[i].x;

}

if(leap[change[i].ii]==0)

{

A[change[i].ii].x1=A[change[i].ii+1].x1=j;

leap[change[i].ii]=1;

}

else  A[change[i].ii].x2=A[change[i].ii+1].x2=j;

}

sort(A+1,A+1+n,cmp2);

memset(num,0,sizeof(num));

update(1,j,A[1].x1,A[1].x2,1,1);

double area=0;

for(i=2;i<=n;i++)

{    

area+=find(1,j,1)*(A[i].y-A[i-1].y);

if(A[i].flash==1)

update(1,j,A[i].x1,A[i].x2,1,1);

else update(1,j,A[i].x1,A[i].x2,-1,1);

}

printf("Test case #%d\n",d++);

printf("Total explored area: %.2lf\n",area);

printf("\n");

}

return 0;

}