小群體-拆解逐步完成版

 ss = [0,1,2,3,4,5,6,7,8,9]

f = [4, 7, 2, 9, 6, 0, 8, 1, 5, 3]

# 1：找到第一群'

# g = []

# cur = 0

# while cur not in g:

#   g.append(cur)

#   cur = f[cur]

# print(g)

# 2：'找到每一群'

# for s in ss:

#   g = []

#   cur = s

#   while cur not in g:

#     g.append(cur)

#     cur = f[cur]

#   print(g)

# 3： '找到每一群，去重覆群'

# v = []

# for s in ss:

#   g = []

#   cur = s

#   if s not in v:

#     while cur not in g:

#       g.append(cur)

#       v.append(cur)

#       cur = f[cur]

#     print(g)

    

# 4： '找到每一群，去重覆群，算出共幾群'

v = []

gs = []

for s in ss:

  g = []

  cur = s

  if s not in v:

    while cur not in g:

      g.append(cur)

      v.append(cur)

      cur = f[cur]

    print(g)

    gs.append(g)

print('共',len(gs),'群')

Output:

[0, 4, 6, 8, 5]

[1, 7]

[2]

[3, 9]

共 4 群