Division problem - MarisaOJ: Marisa Online Judge

Given a set

A

$A$ consisting of

n

$n$ distinct integers. There are

n \times (n - 1) \times (n - 2)

$n \times (n-1) \times (n-2)$ ways to choose three integers

a, b, c

$a, b, c$ from the set. Calculate the sum of

⌊ \frac{a}{b} ⌋ ⌊ \frac{a}{c} ⌋ ⌊ \frac{b}{c} ⌋

$\lfloor \frac{a}{b} \rfloor \lfloor \frac{a}{c} \rfloor \lfloor \frac{b}{c} \rfloor$ for all ways to choose three integers

a, b, c

$a, b, c$ . ### Input - The first line contains an integer

n

$n$ . - The second line contains

n

$n$ distinct integers in the set

a

$a$ . ### Output - Print the sum of

⌊ \frac{a}{b} ⌋ ⌊ \frac{a}{c} ⌋ ⌊ \frac{b}{c} ⌋

$\lfloor \frac{a}{b} \rfloor \lfloor \frac{a}{c} \rfloor \lfloor \frac{b}{c} \rfloor$ modulo

2^{32}

$2^{32}$ for all choices. ### Constraints -

1 \leq n \leq 5000

$1 \leq n \leq 5000$ . - The elements are positive integers not exceeding

5000

$5000$ . ### Example Input:

41234

$4 1 2 3 4$

Output:

36

$36$

Topic

Math

Rating

1900

Solution (1)

Solution