def find(self, x: int) -> int:
if self.fa[x] != x:
self.fa[x] = self.find(self.fa[x])
return self.fa[x]单循环路径压缩：
def find(self, x: int) -> int:
while x != self.fa[x]:
self.fa[x] = self.fa[self.fa[x]]
x = self.fa[x]
return x双循环路径压缩：
def find(self, x: int) -> int:
root = x
while root != self.fa[root]:
root = self.fa[root]
while x != root:
x, self.fa[x] = self.fa[x], root
return root带权并查集路径压缩：
def find(self, x: int) -> int:
root, tot = x, 0
while self.fa[root] != root:
tot += self.dis[root]
root = self.fa[root]
while self.fa[x] != root:
fa, tmp = self.fa[x], self.dis[x]
self.dis[x] = tot
tot -= tmp
self.fa[x] = root
x = fa
return root