Counting StarsTime Limit: 4000/2000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 246 Accepted Submission(s): 27
Problem Description Little A is an astronomy lover, and he has found that the sky was so beautiful!
So he is counting stars now!
There are n stars in the sky, and little A has connected them by m non-directional edges.
It is guranteed that no edges connect one star with itself, and every two edges connect different pairs of stars.
Now little A wants to know that how many different "A-Structure"s are there in the sky, can you help him?
An "A-structure" can be seen as a non-directional subgraph G, with a set of four nodes V and a set of five edges E.
If $V=(A,B,C,D)$ and $E=(AB,BC,CD,DA,AC)$, we call G as an "A-structure".
It is defined that "A-structure" $G_1=V_1+E_1$ and $G_2=V_2+E_2$ are same only in the condition that $V_1=V_2$ and $E_1=E_2$.
Input There are no more than 300 test cases.
For each test case, there are 2 positive integers n and m in the first line.
$2\le n \le 10^5$, $1 \le m \le min(2 \times 10^5,\frac{n(n-1)}{2})$
And then m lines follow, in each line there are two positive integers u and v, describing that this edge connects node u and node v.
$1 \leq u,v \leq n$
$\sum{n} \leq 3 \times 10^5$,$\sum{m} \leq 6 \times 10^5$
Output For each test case, just output one integer--the number of different "A-structure"s in one line.
Sample Input 4 5
1 2
2 3
3 4
4 1
1 3
4 6
1 2
2 3
3 4
4 1
1 3
2 4
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