P12548 [UOI 2025] Manhattan Pairing

Description

For a pair of points on the Cartesian plane $(x_1, y_1)$ and $(x_2, y_2)$, we define the *Manhattan distance* between them as $|x_1-x_2|+|y_1-y_2|$. For example, for the pair of points $(4, 1)$ and $(2, 7)$, the *Manhattan distance* between them is $|4-2|+|1-7| = 2+6 = 8$. You are given $2 \cdot n$ points on the Cartesian plane, whose coordinates are integers. **All $y$-coordinates of the given points are either $0$ or $1$.** Split the given points into $n$ pairs such that each of these points belongs to exactly one pair, and the maximum *Manhattan distance* between the points of one pair is minimized.

Input Format

The first line contains a single integer $n$ $(1 \le n \le 10^5)$. In the following $2 \cdot n$ lines, each line contains two integers $x_i$ and $y_i$ $(0 \le x_i \le 10^9, 0 \le y_i \le 1)$ --- the coordinates of the corresponding point.

Output Format

Output a single integer --- the maximum *Manhattan distance* between the points of one pair in the optimal partition.

Explanation/Hint

In the second example, the pairing $[(18, 0), (14, 0)]$, $[(3, 0), (1, 0)]$, and $[(8, 0), (10, 0)]$ is the only optimal partition. The *Manhattan distances* between the points of one pair in this partition are $4$, $2$, and $2$, respectively. In the third example, the pairing $[(0, 1), (2, 1)]$, $[(2, 1), (3, 0)]$, $[(3, 0), (5, 0)]$, and $[(5, 1), (6, 0)]$ is an optimal partition. All *Manhattan distances* between the points of one pair in this partition are equal to $2$. Illustration for the third example ![](https://cdn.luogu.com.cn/upload/image_hosting/g9n17g5v.png) ### Scoring - ($2$ points): $n = 1$; - ($3$ points): $x_i = 0$ for $1 \le i \le 2\cdot n$; - ($4$ points): $n \le 4$; - ($11$ points): $n \le 10$; - ($14$ points): $y_i = 0$ for $1 \le i \le 2\cdot n$; - ($10$ points): $x_i \neq x_j$ for $1 \le i < j \le 2\cdot n$; - ($29$ points): $n \le 1000$; - ($27$ points): no additional restrictions.