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Time Limit: 6 s Memory Limit: 512 MB Total points: 100

#1838. 智力实现

Statistics

在坐标平面上有 $n$ 个矩形,其边与坐标轴平行。第 $i$ 个矩形覆盖了所有满足 $l_i \le x \le r_i$ 且 $d_i \le y \le u_i$ 的点 $(x, y)$。

为简化起见,对于任意 $i \neq j$,满足 $l_i \neq l_j$,$r_i \neq r_j$,$l_i \neq r_j$,$d_i \neq d_j$,$u_i \neq u_j$,$d_i \neq u_j$。

计算满足 $1 \le i < j < k \le n$ 的三元组 $(i, j, k)$ 的数量,使得第 $i$ 个、第 $j$ 个和第 $k$ 个矩形两两不相交(即任意两个矩形之间没有公共点)。

输入格式

第一行包含一个整数 $n$ ($1 \le n \le 2 \cdot 10^5$),表示矩形的数量。

接下来的 $n$ 行中,第 $i$ 行包含四个整数,描述第 $i$ 个矩形:$l_i, r_i, d_i, u_i$ ($-10^9 \le l_i < r_i \le 10^9$, $-10^9 \le d_i < u_i \le 10^9$)。

保证对于任意 $i \neq j$,满足 $l_i \neq l_j$,$r_i \neq r_j$,$l_i \neq r_j$,$d_i \neq d_j$,$u_i \neq u_j$,$d_i \neq u_j$。

输出格式

输出满足 $1 \le i < j < k \le n$ 且第 $i$ 个、第 $j$ 个和第 $k$ 个矩形两两不相交的三元组数量。

样例

样例输入 1

5
1 5 1 5
4 8 2 6
3 7 3 7
2 6 28 32
42 46 42 46

样例输出 1

3

样例输入 2

6
1 8 6 10
2 5 3 12
3 4 15 20
0 9 2 22
-5 22 -2 23
-7 11 -1 17

样例输出 2

0

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