问题描述 :
You are responsible for inspecting the trees located in a park, to make sure they remain healthy. The location of each tree is given to you as a point in the twodimensional plane, distinct from that of every other tree. Due to recentlyreplanted grass, you are only allowed to walk through the park along a collection of paths. Each path is described by an infinite-length horizontal or vertical line in the two-dimensional plane. No tree lies on any path.
You are concerned that it may not be possible to view all the trees in the park from the paths. In particular, a tree is visible only if you can view it by standing on some path while facing in a direction perpendicular to that path; there must be no intervening tree that obstructs your view. Given the geometrical configuration of the park, please report the number of visible trees.
输入:
There will be multiple input sets. For each input set, the first line will contain two integers, N and M , ( 0 < N, M<=100000 ), separated by a space. N is the number of trees, and M is the number of paths.
The next N lines each contain two space-separated integers, X and Y , specifying the coordinates of a tree. X and Y may be any 32-bit integers.
The next M lines each describe a path (a vertical or horizontal line). They have the form x = K or y = K , with no spaces. K may be any 32-bit integer. x and y will be lower case.
End of the input is signified by a line with two space-separated 0′s.
输出:
There will be multiple input sets. For each input set, the first line will contain two integers, N and M , ( 0 < N, M<=100000 ), separated by a space. N is the number of trees, and M is the number of paths.
The next N lines each contain two space-separated integers, X and Y , specifying the coordinates of a tree. X and Y may be any 32-bit integers.
The next M lines each describe a path (a vertical or horizontal line). They have the form x = K or y = K , with no spaces. K may be any 32-bit integer. x and y will be lower case.
End of the input is signified by a line with two space-separated 0′s.
样例输入:
6 3
-1 3
4 2
6 2
6 3
6 4
4 3
x=0
y=-1
y=5
1 2
2 3
x=5
y=5
0 0
样例输出:
5
1
http://blog.csdn.net/powerfulrobin/article/details/54600544
http://fanyi.baidu.com/?aldtype=85#en/zh/a%20walk%20in%20the%20park