Problem F
Fljúgandi Furðuhlutir Forðast Fókus
Languages
en
is
As is well known, the Earth is of course flat and is monitored by unscrupulous aliens who wish to make sure no one finds out about this secret flatness. To this end the aliens must make sure no one can get a clear picture of their spaceships.
The aliens thus maintain a database of where each individual is located and the quality of their cameras. From this they can calculate a minimum radius they have to stay out of for any given individual. This however complicates the aliens travel plans significantly. If too many individuals obtain good cameras some travel plans might not just be slowed down but made outright impossible. Can you help determine when this occurs? Because of the unusual alien spaceship design all travel plans assume that the spaceships stay at a fixed height above the ground.
Input
The first line of input contains a positive integer $n$, the number of individuals being monitored, and an integer $h$, the height above the ground at which the spaceship stays. Initially no one has a camera. You may assume that $1 \leq n \leq 5 \cdot 10^4$ and $0 \leq h \leq 10^9$. Next there are two lines describing the starting and desired ending position of the spaceship, each given by two integers giving the $x$ and $y$-coordinates, respectively. Next there are $n$ lines, each with two integers $x, y$. The $i$-th line gives the coordinates of the $i$-th individual.
Next there is a line with a single positive integer $m$, the number of camera purchases. You may assume $1 \leq m \leq 10^5$. Then $m$ lines follow where the $i$-th line describes the $i$-th camera purchase. Each line contains an integer $j_i$, the index of the individual buying the camera, and an integer $r_i$ giving the corresponding minimum radius that the spaceship has to stay outside of.
The minimum radius for a given individual is always given by the best camera they have access to. You may assume $1 \leq j_i \leq n$ and $1 \leq r_i \leq 10^9$. All coordinates in the input have a minimum value of $10^{-9}$ and a maximum value of $10^9$.
Output
If the $i$-th camera purchase blocks the spaceship from being able to make it from the starting position to the target position print $i$. If it is possible to travel between the starting and target location while staying outside of the cameras’ views after all camera purchases, instead print $-1$. The purchases are made in the same order as they appear in the input.
Sample Input 1 | Sample Output 1 |
---|---|
4 0 5 5 20 20 0 0 10 0 0 10 10 10 6 1 6 2 2 3 6 4 6 2 4 2 6 |
6 |
Sample Input 2 | Sample Output 2 |
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4 0 4 5 5 5 0 0 10 0 0 10 10 10 4 1 6 2 6 3 6 4 6 |
-1 |
Sample Input 3 | Sample Output 3 |
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2 10 -5 0 5 0 5 0 0 0 2 1 10 2 100 |
2 |