gold_Photo_Op — USACO January_Contest
Task type: batch | Time limit: 2 s | Memory limit: 256 MB | Difficulty: 21
Algorithms: shortest path, geometry, convex hull, dynamic programming

Farmer John's farm is full of lush vegetation and every cow wants a photo of its
natural beauty. Unfortunately, Bessie still has places to be, but she doesn't
want to disrupt any  photo ops.
Bessie is currently standing at $(X,0)$ on the XY-plane and she wants to get to
$(0,Y)$ ($1\le X,Y\le 10^6$). Unfortunately, $N$ ($1 \leq N \leq 3 \cdot 10^5$)
other cows have decided to pose on the $X$ axis. More specifically, cow $i$ will
be positioned at $(x_i,0)$ with a photographer at $(0,y_i)$ where
$(1 \leq x_i,y_i \leq 10^6)$ ready to take their picture. They will begin posing
moments before time $s_i$ ($1 \leq s_i < T$) and they will keep posing for a
very long time (they have to get their picture just right). Here,
$1\le T\le N+1$.
Bessie knows the schedule for every cow's photo op, and she will take the
shortest Euclidean distance to get to her destination, without crossing the line
of sight from any photographer to their respective cow (her path will consist of
one or more line segments).
If Bessie leaves at time $t$, she will avoid the line of sights for all 
photographer/cow pairs that started posing at time $s_i \le t$, and let  the
distance to her final destination be $d_t$. Determine the values of 
$\lfloor d_t\rfloor$ for each integer $t$ from $0$ to $T-1$ inclusive.
INPUT FORMAT (input arrives from the terminal / stdin):
The first line of input contains $N$ and $T$, representing the number of cows
posing on the $x$-axis and the timeframe that Bessie could leave at.
The second line of input contains $X$ and $Y$, representing Bessie's starting $X$
coordinate and her target $Y$ coordinate respectively.
The next $N$ lines contain $s_i$ $x_i$ and $y_i$. It is guaranteed that all
$x_i$ are distinct from each other and $X$, and all $y_i$ are distinct from each
other and $Y$. All $s_i$ will be given in increasing order, where
$s_i \leq s_{i+1}$.
OUTPUT FORMAT (print output to the terminal / stdout):
Print $T$ lines, with the $t$th (0-indexed) line containing
$\lfloor d_t\rfloor$.
SAMPLE INPUT:
4 5
6 7
1 7 5
2 4 4
3 1 6
4 2 9
SAMPLE OUTPUT:
9
9
9
10
12
SAMPLE INPUT:
2 3
10 7
1 2 10
1 9 1
SAMPLE OUTPUT:
12
16
16
For $t=0$ the answer is $\lfloor \sqrt{149} \rfloor=12$.
For $t=1$ the answer is $\lfloor 14+\sqrt 5\rfloor=16$.
SAMPLE INPUT:
5 6
8 9
1 3 5
1 4 1
3 10 7
4 9 2
5 6 6
SAMPLE OUTPUT:
12
12
12
12
14
14
For $t=5$ the answer is $\lfloor 1+\sqrt{9^2+7^2}+2\rfloor=14$. Path:
$(8,0)\to (9,0)\to (0,7)\to (0,9)$
SCORING:
Inputs 4-6: $N\le 100$
Inputs 7-9: $N\le 3000$
Inputs 10-12: $T\le 10$
Inputs 13-18: No additional constraints
Problem credits: Suhas Nagar

Starter code: