Method union

python/2709-greatest-common-divisor-traversal.py:12–22

(self, x, y)

        return self.par[x]

    def union(self, x, y):
        px, py = self.find(x), self.find(y)
        if px == py:
            return
        if self.size[px] < self.size[py]:
            self.par[px] = py
            self.size[py] += self.size[px]
        else:
            self.par[py] = px
            self.size[px] += self.size[py]
        self.count -=1

class Solution:
    def canTraverseAllPairs(self, nums: List[int]) -> bool: