P8337 [CF2002C] Black Circles
普及-
题目描述

There are $n$ circles on a two-dimensional plane. The $i$-th circle is centered at $(x_i,y_i)$. Initially, all circles have a radius of $0$.

The circles' radii increase at a rate of $1$ unit per second.

You are currently at $(x_s,y_s)$; your goal is to reach $(x_t,y_t)$ without touching the circumference of any circle (including the moment you reach $(x_t,y_t)$). You can move in any direction you want. However, your speed is limited to $1$ unit per second.

Please determine whether this is possible.

Input

Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1\le t\le10^4$). The description of the test cases follows.

The first line of each test case contains a single integer $n$ ($1\le n\le10^5$) — the number of circles.

The next $n$ lines each contain two integers $x_i$, $y_i$ ($1\le x_i,y_i\le10^9$) — the center of each circle.

The final line contains four integers $x_s$, $y_s$, $x_t$, $y_t$ ($1\le x_s,y_s,x_t,y_t\le10^9$) — the coordinates of the starting point and the goal, respectively.

It is guaranteed that these $n+2$ points are distinct.

It is guaranteed that the sum of $n$ over all testcases does not exceed $10^5$.

Output

For each test case, output $\texttt{YES}$ if it is possible to reach the goal without touching the circle boundaries, and output $\texttt{NO}$ otherwise.

You can output $\texttt{Yes}$ and $\texttt{No}$ in any case (for example, strings $\texttt{yEs}$, $\texttt{yes}$, $\texttt{Yes}$, and $\texttt{YES}$ will be recognized as a positive response).

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
7 3 2 5 2 14 10 13 4 9 9 7 3 10 11 6 9 12 12 14 13 4 8 1 5 7 12 6 11 13 2 1000000000 2 2 1000000000 1 1 2 2 1 999999998 1000000000 999999999 999999999 1 1 1 1000000000 1 1 1000000000 1 1 10 989237121 2397081 206669655 527238537 522705783 380636165 532545346 320061691 207818728 199485303 884520552 315781807 992311437 802563521 205138355 324818663 223575704 395073023 281560523 236279118 216941610 572010615 323956540 794523071
样例输出
YES NO YES YES YES NO YES
提示

In the first test case, a feasible way of movement is as follows.