POJ訓練計劃1177_Picture(掃描線/線段樹+離散)
解題報告
題意：
求矩形周長和。
思路：
左掃上掃，掃過了。
#include
#include
#include
#include
#include
using namespace std;
struct Seg {
int lx,rx,ly,ry,h,v;
friend bool operator < (Seg a,Seg b)
{
return a.hr||qr>1;
update1(rt<<1,l,mid,ql,qr,v);
update1(rt<<1|1,mid+1,r,ql,qr,v);
push_up1(rt,l,r);
}
void push_up2(int rt,int l,int r)
{
if(lz[rt]) {
sum[rt]=_hy[r+1]-_hy[l];
} else sum[rt]=sum[rt<<1]+sum[rt<<1|1];
}
void update2(int rt,int l,int r,int ql,int qr,int v)
{
if(ql>r||qr>1;
update2(rt<<1,l,mid,ql,qr,v);
update2(rt<<1|1,mid+1,r,ql,qr,v);
push_up2(rt,l,r);
}
int main()
{
int lx,rx,ly,ry,n,i,j;
scanf("%d",&n);
for(i=0; i
Picture
Time Limit: 2000MS
Memory Limit: 10000K
Total Submissions: 10332
Accepted: 5485
Description
A number of rectangular posters, photographs and other pictures of the same shape are pasted on a wall. Their sides are all vertical or horizontal. Each rectangle can be partially or totally covered by the others. The length of the boundary of the union of
all rectangles is called the perimeter.
Write a program to calculate the perimeter. An example with 7 rectangles is shown in Figure 1.
The cZ喎?http://www.Bkjia.com/kf/ware/vc/" target="_blank" class="keylink">vcnJlc3BvbmRpbmcgYm91bmRhcnkgaXMgdGhlIHdob2xlIHNldCBvZiBsaW5lIHNlZ21lbnRzIGRyYXduIGluIEZpZ3VyZSAyLiA8YnI+CjxjZW50ZXI+PGltZyBzcmM9"http://www.2cto.com/uploadfile/Collfiles/20140813/20140813085758254.jpg" alt="\">
The vertices of all rectangles have integer coordinates.
Input
Your program is to read from standard input. The first line contains the number of rectangles pasted on the wall. In each of the subsequent lines, one can find the integer coordinates of the lower left vertex and the upper right vertex of each rectangle. The
values of those coordinates are given as ordered pairs consisting of an x-coordinate followed by a y-coordinate.
0 <= number of rectangles < 5000
All coordinates are in the range [-10000,10000] and any existing rectangle has a positive area.
Output
Your program is to write to standard output. The output must contain a single line with a non-negative integer which corresponds to the perimeter for the input rectangles.
Sample Input
7
-15 0 5 10
-5 8 20 25
15 -4 24 14
0 -6 16 4
2 15 10 22
30 10 36 20
34 0 40 16
Sample Output
228
Source
IOI 1998
