内容目录
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Language:
Atlantis
Description
There are several ancient Greek texts that contain descriptions of the fabled island Atlantis. Some of these texts even include maps of parts of the island. But unfortunately, these maps describe different regions of Atlantis. Your friend Bill has to know the
total area for which maps exist. You (unwisely) volunteered to write a program that calculates this quantity. Input
The input consists of several test cases. Each test case starts with a line containing a single integer n (1 <= n <= 100) of available maps. The n following lines describe one map each. Each of these lines contains four numbers x1;y1;x2;y2 (0 <= x1 < x2 <=
100000;0 <= y1 < y2 <= 100000), not necessarily integers. The values (x1; y1) and (x2;y2) are the coordinates of the top-left resp. bottom-right corner of the mapped area. The input file is terminated by a line containing a single 0. Don't process it. Output
For each test case, your program should output one section. The first line of each section must be "Test case #k", where k is the number of the test case (starting with 1). The second one must be "Total explored area: a", where a is the total explored area
(i.e. the area of the union of all rectangles in this test case), printed exact to two digits to the right of the decimal point. Output a blank line after each test case. Sample Input 2 10 10 20 20 15 15 25 25.5 0 Sample Output Test case #1 Total explored area: 180.00 Source |
同Hdu 1542，不过数据变水……
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cmath>
#include<cctype>
#include<iostream>
#include<functional>
#include<algorithm>
#include<map>
using namespace std;
#define MAXN (2000+10)
#define MAXT (1000*2*10)
#define Lson (x<<1)
#define Rson ((x<<1)^1)
int tt,n,size;
double x[MAXN];
struct SegMent
{
double x1,x2,h;
int type;
SegMent(){}
SegMent(double _x1,double _x2,double _h,int _type):x1(_x1),x2(_x2),h(_h),type(_type){}
friend bool operator<(const SegMent a,const SegMent b){return a.h<b.h; }
}a[MAXN];
map<double , int> hpos;
double len[MAXT];
struct SegMentTree
{
int n,M,cnt[MAXT];
double sum[MAXT];
int mark[MAXT];
void fillchar(int _n)
{
n=_n;
memset(cnt,0,sizeof(cnt));
memset(sum,0,sizeof(sum));
memset(mark,0,sizeof(mark));
M=1;while (M-2<n) M<<=1;
x[0]=0;memset(len,0.0,sizeof(len));
for (int i=M+1;i<=M+size;i++) len[i]=x[i-M]-x[i-M-1];
for (int i=M-1;i>0;i--) len[i]=len[i<<1]+len[(i<<1)^1];
}
void pushup(int x)
{
sum[x]=cnt[x]?len[x]:(x>=M?0:sum[Lson]+sum[Rson]);
}
void update(int x)
{
for (;x;x>>=1)
{
pushup(x);
}
}
void insert(int l,int r,int c)
{
int ll=l-1+M,rr=r+1+M;
for (l=l-1+M,r=r+1+M;l^r^1;l>>=1,r>>=1)
{
if (~l&1) {cnt[l+1]+=c;pushup(l+1);} /*改变sum的值 */
if (r&1) {cnt[r-1]+=c;pushup(r-1);}
}
update(ll);update(rr);
}
}t;
int main()
{
// freopen("Hdu1542.in","r",stdin);
tt=0;
while (scanf("%d",&n)!=EOF)
{
tt++;
if (!n) break;
for (int i=1;i<=2*n;i+=2)
{
double x1,y1,x2,y2;
scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
x[i]=x1;x[i+1]=x2;
a[i]=SegMent(x1,x2,y1,1);
a[i+1]=SegMent(x1,x2,y2,-1);
}
sort(a+1,a+2*n+1);
sort(x+1,x+2*n+1);
size=unique(x+1,x+2*n+1)-(x+1);
for (int i=1;i<=size;i++) hpos[x[i]]=i;
t.fillchar(size);
double ans=0;a[0].h=a[1].h;
for (int i=1;i<=2*n;i++)
{
ans+=(a[i].h-a[i-1].h)*t.sum[1];
t.insert(hpos[a[i].x1]+1,hpos[a[i].x2],a[i].type);
}
printf("Test case #%dnTotal explored area: %.2lfnn",tt,ans);
}
return 0;
}