测评会员优惠活动进行中 · 开通 VIP,有效期内测评不限次 VIP 优惠中 · 测评不限次 立即查看

A14597. Training Session

编程题 普及/提高-

题目描述

Monocarp is the coach of the Berland State University programming teams. He decided to compose a problemset for a training session for his teams.

Monocarp has $n$ problems that none of his students have seen yet. The $i$ -th problem has a topic $a_i$ (an integer from $1$ to $n$ ) and a difficulty $b_i$ (an integer from $1$ to $n$ ). All problems are different, that is, there are no two tasks that have the same topic and difficulty at the same time.

Monocarp decided to select exactly $3$ problems from $n$ problems for the problemset. The problems should satisfy at least one of two conditions (possibly, both):

- the topics of all three selected problems are different;
- the difficulties of all three selected problems are different.

Your task is to determine the number of ways to select three problems for the problemset.

输入格式

The first line contains a single integer $t$ ( $1 \le t \le 50000$ ) — the number of testcases.

The first line of each testcase contains an integer $n$ ( $3 \le n \le 2 \cdot 10^5$ ) — the number of problems that Monocarp have.

In the $i$ -th of the following $n$ lines, there are two integers $a_i$ and $b_i$ ( $1 \le a_i, b_i \le n$ ) — the topic and the difficulty of the $i$ -th problem.

It is guaranteed that there are no two problems that have the same topic and difficulty at the same time.

The sum of $n$ over all testcases doesn't exceed $2 \cdot 10^5$ .

输出格式

Print the number of ways to select three training problems that meet either of the requirements described in the statement.

输入输出样例

输入 #1
2
4
2 4
3 4
2 1
1 3
5
1 5
2 4
3 3
4 2
5 1
输出 #1
3
10

说明/提示

In the first example, you can take the following sets of three problems:

- problems $1$ , $2$ , $4$ ;
- problems $1$ , $3$ , $4$ ;
- problems $2$ , $3$ , $4$ .

Thus, the number of ways is equal to three.
上一题 去做题 下一题