Count Ways to Make Array With Product
<p>You are given a 2D integer array, <code>queries</code>. For each <code>queries[i]</code>, where <code>queries[i] = [n<sub>i</sub>, k<sub>i</sub>]</code>, find the number of different ways you can place positive integers into an array of size <code>n<sub>i</sub></code> such that the product of the integers is <code>k<sub>i</sub></code>. As the number of ways may be too large, the answer to the <code>i<sup>th</sup></code> query is the number of ways <strong>modulo</strong> <code>10<sup>9</sup> + 7</code>.</p>

<p>Return <em>an integer array </em><code>answer</code><em> where </em><code>answer.length == queries.length</code><em>, and </em><code>answer[i]</code><em> is the answer to the </em><code>i<sup>th</sup></code><em> query.</em></p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> queries = [[2,6],[5,1],[73,660]]
<strong>Output:</strong> [4,1,50734910]
<strong>Explanation:</strong>&nbsp;Each query is independent.
[2,6]: There are 4 ways to fill an array of size 2 that multiply to 6: [1,6], [2,3], [3,2], [6,1].
[5,1]: There is 1 way to fill an array of size 5 that multiply to 1: [1,1,1,1,1].
[73,660]: There are 1050734917 ways to fill an array of size 73 that multiply to 660. 1050734917 modulo 10<sup>9</sup> + 7 = 50734910.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> queries = [[1,1],[2,2],[3,3],[4,4],[5,5]]
<strong>Output:</strong> [1,2,3,10,5]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= queries.length &lt;= 10<sup>4</sup> </code></li>
	<li><code>1 &lt;= n<sub>i</sub>, k<sub>i</sub> &lt;= 10<sup>4</sup></code></li>
</ul>
Array; Math; Dynamic Programming; Combinatorics; Number Theory
const n = 1e4 + 20
const mod = 1e9 + 7

var f = make([]int, n)
var g = make([]int, n)
var p = make([][]int, n)

func qmi(a, k, p int) int {
	res := 1
	for k != 0 {
		if k&1 == 1 {
			res = res * a % p
		}
		k >>= 1
		a = a * a % p
	}
	return res
}

func init() {
	f[0], g[0] = 1, 1
	for i := 1; i < n; i++ {
		f[i] = f[i-1] * i % mod
		g[i] = qmi(f[i], mod-2, mod)
		x := i
		for j := 2; j <= x/j; j++ {
			if x%j == 0 {
				cnt := 0
				for x%j == 0 {
					cnt++
					x /= j
				}
				p[i] = append(p[i], cnt)
			}
		}
		if x > 1 {
			p[i] = append(p[i], 1)
		}
	}
}

func comb(n, k int) int {
	return (f[n] * g[k] % mod) * g[n-k] % mod
}

func waysToFillArray(queries [][]int) (ans []int) {
	for _, q := range queries {
		n, k := q[0], q[1]
		t := 1
		for _, x := range p[k] {
			t = t * comb(x+n-1, n-1) % mod
		}
		ans = append(ans, t)
	}
	return
}