6月8日

leetcode 每日一题 https://leetcode-cn.com/problems/satisfiability-of-equality-equations/

思路：并查集  先把所有==合并，再将所有 ！=查找。如果是同一个父亲就return false 。

class Solution:
    def equationsPossible(self, equations: 'List[str]') -> 'bool':
        fa={chr(i):chr(i) for i in range(97,125)}

        def find(x):
            if x!= fa[x]:
                fa[x] = find(fa[x])
            return fa[x]

        for it in  equations:
            if(it[1]=="="):
                fa[find(it[0])]=find(it[3])

        for it in equations:
            if (it[1] == "!"):
                if(find(it[3])==find(it[0])):
                    return False


        return True