you give tree consist n node you generate array tree mark node oneInitially node mark node equiprobably choose mark entire tree after node mark node equiprobably choose marked set unmarked node edge mark node it show process mark node tree the final array list node label order time node markedFind expect number inversion array generate tree aforementione processthe number inversion array number pair index j j a_i a_j for example array 4 1 3 2 contain 4 inversion 1 2 1 3 1 4 3 4