102072: [AtCoder]ABC207 C - Many Segments

Memory Limit：256 MB Time Limit：2 S
Judge Style：Text Compare Creator：
Submit：0 Solved：0

Description

Score : $300$ points

Problem Statement

You are given $N$ intervals numbered $1$ through $N$, that are as follows:

  • if $t_i=1$, Interval $i$ is $[l_i,r_i]$;
  • if $t_i=2$, Interval $i$ is $[l_i,r_i)$;
  • if $t_i=3$, Interval $i$ is $(l_i,r_i]$;
  • if $t_i=4$, Interval $i$ is $(l_i,r_i)$.

How many pairs of integers $(i,j)$ satisfying $1 \leq i \lt j \leq N$ are there such that Interval $i$ and Interval $j$ intersect?

What are $[X,Y],[X,Y),(X,Y],(X,Y)$?
  • A closed interval $[X,Y]$ is an interval consisting of all real numbers $x$ such that $X \leq x \leq Y$.
  • A half-open interval $[X,Y)$ is an interval consisting of all real numbers $x$ such that $X \leq x < Y$.
  • A half-open interval $(X,Y]$ is an interval consisting of all real numbers $x$ such that $X < x \leq Y$.
  • A open interval $(X,Y)$ is an interval consisting of all real numbers $x$ such that $X < x < Y$.
Roughly speaking, square brackets $[]$ mean the endpoint is included, and curly brackets $()$ mean the endpoint is excluded.

Constraints

  • $2 \leq N \leq 2000$
  • $1 \leq t_i \leq 4$
  • $1 \leq l_i \lt r_i \leq 10^9$
  • All values in input are integers.

Input

Input is given from Standard Input in the following format:

$N$
$t_1$ $l_1$ $r_1$
$t_2$ $l_2$ $r_2$
$\hspace{1cm}\vdots$
$t_N$ $l_N$ $r_N$

Output

Print the number of pairs of integers $(i,j)$ such that Interval $i$ and Interval $j$ intersect.

Sample Input 1

3
1 1 2
2 2 3
3 2 4

Sample Output 1

2

As defined in the Problem Statement, Interval $1$ is $[1,2]$, Interval $2$ is $[2,3)$, and Interval $3$ is $(2,4]$.

There are two pairs of integers $(i,j)$ such that Interval $i$ and Interval $j$ intersect: $(1,2)$ and $(2,3)$. For the first pair, the intersection is $[2,2]$, and for the second pair, the intersection is $(2,3)$.

Sample Input 2

19
4 210068409 221208102
4 16698200 910945203
4 76268400 259148323
4 370943597 566244098
1 428897569 509621647
4 250946752 823720939
1 642505376 868415584
2 619091266 868230936
2 306543999 654038915
4 486033777 715789416
1 527225177 583184546
2 885292456 900938599
3 264004185 486613484
2 345310564 818091848
1 152544274 521564293
4 13819154 555218434
3 507364086 545932412
4 797872271 935850549
2 415488246 685203817

Sample Output 2

102

Input

题意翻译

## 题目翻译 给定 $N$ 个区间，其中第 $i$ 个区间由一个标识符 $t_i$ 及两个端点 $l_i,r_i$ 组成。 - 若 $t_i = 1$，则表示闭区间 $[l_i,r_i]$ - 若 $t_i = 2$，则表示左闭右开区间 $[l_i,r_i)$ - 若 $t_i = 3$，则表示左开右闭区间 $(l_i,r_i]$ - 若 $t_i = 4$，则表示开区间 $(l_i,r_i)$ 其中闭区间指包含端点的区间，用方括号表示。开区间指不包含端点的区间，用圆括号表示。半开半闭区间同理。 现在，请你求出这 $N$ 个区间中相交区间的对数。 ## 样例解释 对于输入样例 $1$，题目中给定的区间为 $[1,2]$，$[2,3)$，和 $(2,4]$。第一个区间和第二个区间相交（均包含整数 $2$），第二个区间和第三个区间相交（均包含任意 $2 < x < 3$ 的实数 $x$）。因此有两对相交区间，答案为 $2$。

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