Heap’s algorithm wiki picture vs algorithm

I'm trying to understand Heap's algorithm from the Wikipedia page and I'm trying to compare the picture with the algorithm and I can't seem to figure it out

this picture is from the wikipedia page

why would it switch the #1 and #2 first, shouldn't it switch the #1 and #4 first?

I'm using java but this is just the code copied from Wikipedia, I understand that there is switching involved for the code in general

    if k = 1 then          output(A)      else          // Generate permutations with kth unaltered          // Initially k == length(A)          generate(k - 1, A)            // Generate permutations for kth swapped with each k-1 initial          for i := 0; i < k-1; i += 1 do              // Swap choice dependent on parity of k (even or odd)              if k is even then                  swap(A[i], A[k-1]) // zero-indexed, the kth is at k-1              else                  swap(A[0], A[k-1])              end if              generate(k - 1, A)            end for      end if  

k is initially 4 so wouldn't it switch A[0] and A[3] first?

Sorry in advance if this is a stupid question...

https://stackoverflow.com/questions/66576314/heap-s-algorithm-wiki-picture-vs-algorithm March 11, 2021 at 12:06PM