Chords#11665
There are points evenly distributed along a circle and numbered from to in clockwise order, starting from a fixed point.
On this circle, chords are given. The -th chord connects points with numbers a_i and b_i. It is guaranteed that all values a_1, \ldots, a_n, b_1, \ldots, b_n are pairwise distinct.
Your task is to determine whether there exists at least one intersection between any two chords.
The first line contains one integer (2 \le n \le 2 \cdot 10^5) — the number of chords. Each of the next lines contains two integers a_i and b_i (1 \le a_i, b_i \le 2n) — the endpoints of the -th chord.
Print "Yes" if there exists at least one intersection between any two chords, and "No" otherwise.
Example 1
Example 2
Example 3