#P3492. Segment

    ID: 2376 远端评测题 2000ms 64MiB 尝试: 0 已通过: 0 难度: (无) 上传者: 标签>2010 ACM-ICPC Multi-University Training Contest(6)——Host by BIT

Segment

Problem Description

In the annual Gaozhong Shuxue Liansai in the kingdom of Henryy, difficult geometry problems often appear. Let’s have a look at a problem:
N (1<=N<=300) segments are on a two dimension Cartesian plane. Your task is to check out whether there is a line that the intersection of the projections of all N segments is non-empty.

Input

The first line contains an integer T, indicating the number of the test cases.
For each test case, the first line contains an integer N, the number of the segments.
Then N lines follows, each has four integers (x1, y1), (x2, y2), indicating the two endpoints of this segment.

Output

For each test case, output a line: if such a line exists, print “Yes”; otherwise, print “No”.

2 2 0 0 1 1 2 1 4 -1 4 6 5 0 1 1 9 0 6 9 7 0 10 7 10 8 7
Yes No