Quick Find

import graphviz
def drawUF(a):
    dot = graphviz.Digraph(comment='Nada')
    n = len(a)
    for i in range(n):
        dot.node(str(i), str(i))
    for i in range(n):
        if i != a[i]:
            dot.edge(str(i), str(a[i]))
    dot.graph_attr['rankdir'] = 'BT'
    return dot

dot = drawUF([0, 0, 9, 9, 9, 6, 6, 7, 8, 9])
#print(dot)
graphviz.Source(dot)

def quickfind(s, a):
    return s[a]

def qfunion(s, a, b):
    pa = quickfind(s, a)
    pb = quickfind(s, b)
    for i in range(len(s)):
        if s[i] == pa:
            s[i] = pb

s = [i for i in range(10)]
dot = drawUF(s)
graphviz.Source(dot)

qfunion(s, 3, 4)
dot = drawUF(s)
graphviz.Source(dot)