Codeforces Round 758 (Div.1 + Div. 2)
E
The Cells on the Paper
Codeforces
2800
原题
← DF →
翻译中…

On an endless checkered sheet of paper, $n$ cells are chosen and colored in three colors, where $n$ is divisible by $3$. It turns out that there are exactly $\frac{n}{3}$ marked cells of each of three colors!

翻译中…

Find the largest such $k$ that it's possible to choose $\frac{k}{3}$ cells of each color, remove all other marked cells, and then select three rectangles with sides parallel to the grid lines so that the following conditions hold:

翻译中…
  • No two rectangles can intersect (but they can share a part of the boundary). In other words, the area of intersection of any two of these rectangles must be $0$.
  • The $i$-th rectangle contains all the chosen cells of the $i$-th color and no chosen cells of other colors, for $i = 1, 2, 3$.
翻译中…

Input

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The first line of the input contains a single integer $n$ — the number of the marked cells ($3 \leq n \le 10^5$, $n$ is divisible by 3).

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The $i$-th of the following $n$ lines contains three integers $x_i$, $y_i$, $c_i$ ($|x_i|,|y_i| \leq 10^9$; $1 \leq c_i \leq 3$), where $(x_i, y_i)$ are the coordinates of the $i$-th marked cell and $c_i$ is its color.

翻译中…

It's guaranteed that all cells $(x_i, y_i)$ in the input are distinct, and that there are exactly $\frac{n}{3}$ cells of each color.

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Output

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Output a single integer $k$ — the largest number of cells you can leave.

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Note

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In the first sample, it's possible to leave $6$ cells with indexes $1, 5, 6, 7, 8, 9$.

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In the second sample, it's possible to leave $3$ cells with indexes $1, 2, 3$.

翻译中…

样例

Input #1
9
2 3 1
4 1 2
2 1 3
3 4 1
5 3 2
4 4 3
2 4 1
5 2 2
3 5 3
Output #1
6
InputCopy OutputCopy
Input #2
3
1 1 1
2 2 2
3 3 3
Output #2
3
InputCopy OutputCopy
题目信息
题号
1608E
时间限制
2 s
内存限制
256 MB
标签
二分
模拟
排序

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