Step by Step solution about How to resolve the algorithm Equilibrium index step by step in the Mathematica / Wolfram Language programming language

The Wolfram programming language code snippet you provided calculates the equilibrium index of a list of numbers. The equilibrium index of a list is the position where the sum of the elements to the left of the index is equal to the sum of the elements to the right of the index.

The code uses the Reap and Sow functions to keep track of the equilibrium indices as they are found. The Reap function is used to create a collector, and the Sow function is used to add elements to the collector.

The Do function is used to iterate over the elements of the list, and the If function is used to check if the sum of the elements to the left of the current index is equal to the sum of the elements to the right of the current index. If the sums are equal, the current index is added to the collector using the Sow function.

After the Do loop has finished, the Reap function is used to retrieve the elements from the collector and return them as a list. The equilibrium index is then extracted from the list by taking the second element of the first row.

equilibriumIndex[data_]:=Reap[
    Do[If[Total[data[[;; n - 1]]] == Total[data[[n + 1 ;;]]],Sow[n]], 
    {n, Length[data]}]][[2, 1]]