Buggy algorithm

Lukas was asked to be solve the following problem: 'given a permutation of numbers 1,..,n, calculate the number of inversions in it, i.e., the number of pairs of numbers i, j from 1..n, such that iSo, for permutation 4,1,2,3, the algorithm would give the answer 0+1+1+1 = 3, and for the permutation 3,4,5,1,2, the answer 0+0+0+3+3 =6. Obviously, this algorithm is wrong (it gives wrong results e.g.