题库练习 Bicolored Segments
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A13583 | Bicolored Segments

时间限制1s
内存限制256MB
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题目描述

You are given $n$ segments $[l_1, r_1], [l_2, r_2], \dots, [l_n, r_n]$ . Each segment has one of two colors: the $i$ -th segment's color is $t_i$ .

Let's call a pair of segments $i$ and $j$ bad if the following two conditions are met:

- $t_i \ne t_j$ ;
- the segments $[l_i, r_i]$ and $[l_j, r_j]$ intersect, embed or touch, i. e. there exists an integer $x$ such that $x \in [l_i, r_i]$ and $x \in [l_j, r_j]$ .

Calculate the maximum number of segments that can be selected from the given ones, so that there is no bad pair among the selected ones.

输入格式

The first line contains a single integer $n$ ( $1 \le n \le 2 \cdot 10^5$ ) — number of segments.

The next $n$ lines contains three integers $l_i, r_i, t_i$ ( $1 \le l_i \le r_i \le 10^9; t_i \in \{1, 2\}$ ) — description of the $i$ -th segment.

输出格式

Print the maximum number of segments that can be selected, so that there is no bad pair among the selected segments.

输入输出样例

输入 #1
3
1 3 1
4 6 2
2 5 1
输出 #1
2
输入 #2
5
5 8 1
1 3 2
3 4 2
6 6 1
2 10 2
输出 #2
4
输入 #3
7
19 20 1
13 15 2
6 11 2
4 10 1
14 17 1
13 13 2
5 9 1
输出 #3
5
C++ 编辑器
输入
输出