Swift implementation of the weighted quick union algorithm, useful for applications requiring percolation

wqu.swift

class WQU {
  
  var data = [0,1,2,3,4,5]
  var size = [1,1,1,1,1,1]
  
  func union(a:Int, b:Int) {
    let i = root(a)
    let j = root(b)
    
    if size[i] >= size[j] {
      size[i] += size[j]
      data[j] = data[i]
    }
    else {
      size[j] += size[i]
      data[i] = data[j]
    }
  }
  
  // get the root
  func root(i:Int) -> Int {
    var j = i
    while j != data[j] {
      j = data[j]
    }
    return j
  }
}

// useage:
var wqu = WQU()

wqu.union(1, b: 5)