1807.
Geohash Grid
时间限制 5000 ms
内存限制 512 MB
Geohash is a procedure of coding map coordinates to scalar values for the purpose of efficient storage and querying of geographical data in databases. In this problem, a map is a $2^n × 2^n$ rectangular grid embedded in a standard coordinate system with the $x$ coordinate growing rightwards and the $y$ coordinate growing upwards. A *map cell* is a unit square aligned with the coordinate axes whose lower-left corner is a point with integer coordinates $( x, y )$ such that $0 ≤ x, y < 2^n$ .
There are a total of $2^{2n}$ cells in a $2^n × 2^n$ map. Given a map cell $c$, its geohash $h ( c )$ is a $2n$-bit non-negative integer constructed bit by bit starting from the most significant bit by setting the *viewport* to the entire map and repeating the following two steps $n$ times:
1. We divide the viewport into two equal areas — the left half and the right half. If the cell $c$ is in the left half, the next bit is $0$, otherwise the next bit is $1$. The new viewport is the area containing the cell $c$.
2. We divide the viewport into two equal areas — the bottom half and the top half. If the cell $c$ is in the bottom half the next bit is $0$, otherwise the next bit is $1$. The new viewport is the area containing the cell $c$.
A *geohash interval* $[ a − b ]$ is a set of cells whose geohash values are between $a$ and $b$, both inclusive. Often, it is useful to approximate a map region with a set of geohash intervals. Given a set of cells $C$, and an integer $t$, an *optimal $t$-approximation* of $C$ is a minimal-area region that contains $C$ and can be described as an union of at most $t$ geohash intervals. Formally, it is a set $S$ of at most $t$ geohash intervals such that:
- Each cell of $C$ is contained in at least one interval in $S$.
- The total number of cells in the union of all intervals in $S$ is minimal possible.
You are given a map region $C$ described as a set of cells in the interior of a polygon whose sides are aligned with the grid. You are also given $q$ target integers $t_1, t_2, ..., t_q$. For each $t_k$ find the area of an
optimal $t_k$ -approximation of $C$.
输入数据
输出数据
The $k$-th line should contain the size of the optimal $t_k$ -approximation of the given region.
样例输入
复制
3
8
1 1
5 1
5 4
3 4
3 8
0 8
0 5
1 5
4
2
3
5
7 \n
\n
· \n
· \n
· \n
· \n
· \n
· \n
· \n
· \n
\n
\n
\n
\n
\n
样例输出
复制
32
30
26
24 \n
\n
\n
\n
样例说明
In the example above, the intervals $[ 3 − 29 ] , [ 33 − 33 ]$ and $[ 36 − 37 ]$ form an optimal $3$-approximation of the given region. The total area of the union of the three intervals is $30$.
