number of events (e.g. accidents, crimes, meetings, housing starts, hits on a web page)

An inversion of a sequence in computer science and discrete mathematics is a pair of terms in that sequence such that the components of those terms are out of their natural order. $\mathrm{inv}(A)=\#\{(A_i,A_j)\mid i<j\mathrm{and}{A}_i>A_j\}$

The number of overturns in the combined column x+y is obtained from the respective number of overturns f and the frequency table c ACLPC L PAST4K.

• $f(x+y)=f(x)+f(y)+{\sum }_i{\sum }_{j}c(x,i)c(y,j)[i>j]$

• Fennic tree and obtained by O(NlogN) python

init(N)
inv = 0
for a in seqs[i]:
    bit_add(a, 1)
    inv += bit_sum(N) - bit_sum(a)

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