Link: https://codeforces.com/problemset/problem/1475/E
combinatorics
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1
7 5
5 1 6 4 1 1 5
sorted:
1 1 1 4 5 5 6
k distinct bloggers = [6, 5, 4, 1]
freq[6] = 1
freq[5] = 2
freq[4] = 1
freq[1] = 3
6 5 5 4 1
freq[6] choose 1
freq[5] choose 2
freq[4] choose 1
freq[1] choose 1
multiply all the values above
highest = k largest numbers
= freq[highest[0]] * freq[highest[1]] * ... * freq[highest[k-1]]
ans: 3
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1
4 2
1 1 1 1
k bloggers = [1]
freq[1] = 4
if freq[a[i]] >= k, then (freq[a[i]] choose k)
ans: 6