Segment

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.

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.

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

2010 ACM-ICPC Multi-University Training Contest（6）——Host by BIT